Portal of Bangladesh Shinebd.com Shiddika Kabir's Recipe Beautiful Muslim Arabic Baby Names

From Wikipedia, the free encyclopedia SMS Moltke[Note 1] was the lead ship of the Moltke-class battlecruisers of the German Imperial Navy, named after the 19th century German field marshal Helmuth von Moltke. Commissioned on 30 September 1911, the ship was the second battlecruiser commissioned into the Imperial Navy. Moltke, along with her sister ship Goeben, was an enlarged version of the previous German battlecruiser design, Von der Tann. The ship was very similar to Von der Tann, but had increased armor protection and two more main guns in an additional turret. Compared to her British rivals—the Indefatigable class—Moltke and her sister Goeben were significantly larger and better armored.[Note 2] The ship participated in most of the major fleet actions conducted by the German Navy during the First World War, including the Battles of Dogger Bank and Jutland in the North Sea, and the Battle of the Gulf of Riga and Operation Albion in the Baltic. Moltke was damaged several times during the war: the ship was hit by heavy caliber gunfire at Jutland, and torpedoed twice by British submarines while on fleet advances. Following the end of the war in 1918, Moltke, along with most of the High Seas Fleet, was interned at Scapa Flow pending a decision by the Allies as to the fate of the fleet. The ship met her end when she was scuttled, along with the rest of the High Seas Fleet, in 1919 to prevent them from falling into British hands. The wreck of Moltke was raised in 1927 and scrapped at Rosyth from 1927 to 1929. Development In a conference in May 1907, the Germany Navy Office decided to follow up the unique[Note 3] Von der Tann battlecruiser with an enlarged design.[4] 44 million marks were allocated for the 1908 fiscal year, which created the possibility of increasing the main guns to 30.5 cm (12 in) in diameter, instead of the 28 cm (11 in) weapons on the preceding design. However, Admiral Alfred von Tirpitz, along with the Construction Department, argued that increasing the number of guns from 8 to 10 would be preferable instead of increasing the size of the previous battery.[4] The General Navy Department held that for the new design to fight in the battle line, 30.5 cm (12 in) guns were necessary. Ultimately, Tirpitz and the Construction Department won the debate, and Moltke was equipped with ten 28 cm (11 in) guns. It was also mandated by the Construction Department that armor protection was to be at least as good as that of Von der Tann. The ship was also to have a top speed of at least 24.5 knots (45.4 km/h).[4] During the design process, the ship's weight continued to grow due to the increase in the size of the citadel, armor thickness, the additions to the ammunition stores, and the rearrangement of the boiler system.[4] The naval arms race between Germany and Britain put a great deal of stress on the Navy design staff, and prompted the decision to build two ships of the new design. They were assigned under the contract names of "Cruiser G" and "Cruiser H." Blohm & Voss received both contracts in 1908; "Cruiser G" was assigned to the 1908–1909 building year, while "Cruiser H" was assigned to 1909–1910.[5] The contract for "Cruiser G" was awarded on 17 September 1908, under building number 200. The keel was laid on 7 December 1908, and the ship was launched on 7 April 1910. "Cruiser G" was commissioned on 30 September 1911, as SMS Moltke.[1] Service record Pre-war At the launching of the ship on 7 April 1910, Helmuth von Moltke the Younger christened the ship after his uncle Helmuth von Moltke the Elder,[6] the Chief of Staff of the Prussian Army in the mid 19th century.[2] On 11 September 1911, a crew composed of dockyard workers transferred the ship from Hamburg to Kiel through the Skagen.[7] On 30 September, the ship was commissioned, under the command of Kapitän zur See von Mann,[2] and replaced Roon in the Reconnaissance Unit. Sea trials continued until 1 April 1912.[7] SMS Moltke in New York in 1912. She was the first and only German capital ship to ever visit the United States. On 11 May 1912 she left Kiel, accompanied by the light cruisers Stettin and Bremen, and arrived off Hampton Roads, Virginia, on 30 May 1912. After touring the East Coast for two weeks, she returned to Kiel on 24 June.[7] In July 1912, Moltke escorted Kaiser Wilhelm II's yacht to Russia. Upon returning, Moltke's commander was replaced by KzS Magnus von Levetzow,[2] and the ship became the Reconnaissance Force flagship until 23 June 1914, when the commander's flag was transferred to the new battlecruiser Seydlitz.[7] There was some consideration given to deploying Moltke to the Far East in order to replace the armored cruiser Scharnhorst, but the plan was abandoned when it became apparent that Goeben needed replacement in the Mediterranean. Moltke was then scheduled to transfer to replace her sister ship, but this plan was interrupted by the outbreak of World War I.[7] World War I As was the case with almost all German capital ships during World War I, Moltke's action was somewhat limited. However, she did participate in most of the major fleet actions conducted by the High Seas Fleet. At the start of the war, the ship was assigned to the I Scouting Group of the High Seas Fleet, under the command of Rear Admiral Franz Hipper.[7] Battle of Heligoland Bight Main article: Battle of Heligoland Bight Shortly after the outbreak of World War I, on 28 August 1914, Moltke participated in the Battle of Heligoland Bight. During the morning, British cruisers from the Harwich Force attacked the German destroyers patrolling the Heligoland Bight. Six German light cruisers—Köln, Strassburg, Stettin, Frauenlob, Stralsund, and Ariadne—responded to the attack and inflicted serious damage to the British raiders. However, the arrival at approximately 13:37 of the British 1st Battlecruiser Squadron, under the command of Vice Admiral David Beatty, quickly put the German ships at a disadvantage.[8] Along with the rest of the I Scouting Group battlecruisers, Moltke was stationed in the Wilhelmshaven Roads on the morning of the battle. By 08:50, Rear Admiral Hipper had requested permission from Admiral Friedrich von Ingenohl, the commander in chief of the High Seas Fleet, to send Moltke and Von der Tann to relieve the beleaguered German cruisers.[9] Moltke was ready to sail by 12:10, but the low tide prevented the ships from being able to pass over the sand bar at the mouth of the Jade Estuary safely. At 14:10, Moltke and Von der Tann were able to cross the Jade bar; Hipper ordered the German cruisers to fall back to his ships, while Hipper himself was about an hour behind in the battlecruiser Seydlitz. At 14:25, the remaining light cruisers—Strassburg, Stettin, Frauenlob, Stralsund, and Ariadne—rendezvoused with the battlecruisers.[10] Seydlitz arrived on the scene by 15:10, while Ariadne succumbed to battle damage and sank. Hipper ventured forth cautiously to search for the two missing light cruisers, Mainz and Köln, which had already sunk. By 16:00, the German flotilla turned around to return to the Jade Estuary, arriving at approximately 20:23.[11] Bombardment of Yarmouth Main article: Raid on Yarmouth On 2 November 1914, Moltke, Rear Admiral Hipper's flagship Seydlitz, Von der Tann, and Blücher along with four light cruisers left the Jade Estuary and steamed towards the English coast.[12] The flotilla arrived off Great Yarmouth at daybreak the following morning and bombarded the port, while the light cruiser Stralsund laid a minefield. The British submarine D5 responded to the bombardment, but struck one of the mines laid by Stralsund and sank. Shortly thereafter, Hipper ordered his ships to turn back to German waters. However, while Hipper's ships were returning to German waters, a heavy fog covered the Heligoland Bight, so the ships were ordered to halt until visibility improved so they could safely navigate the defensive minefields. The armored cruiser Yorck left the Jade without permission, and while en route to Wilhelmshaven made a navigational error that led the ship into one of the German minefields. Yorck struck two mines and quickly sank; the coastal defense ship Hagen was able to save 127 men of the crew.[12] Bombardment of Scarborough, Hartlepool, and Whitby Main article: Raid on Scarborough, Hartlepool and Whitby It was decided by Admiral von Ingenohl that another raid on the English coast was to be carried out, in the hopes of luring a portion of the Grand Fleet into combat, where it could be destroyed.[12] At 03:20 on 15 December, Moltke, Seydlitz, Von der Tann, Derfflinger, and Blücher, along with the light cruisers Kolberg, Strassburg, Stralsund, and Graudenz, and two squadrons of torpedo boats left the Jade.[13] The ships sailed north past the island of Heligoland, until they reached the Horns Reef lighthouse, at which point the ships turned west towards Scarborough. Twelve hours after Hipper left the Jade, the High Seas Fleet, consisting of 14 dreadnoughts and 8 pre-dreadnoughts and a screening force of 2 armored cruisers, 7 light cruisers, and 54 torpedo boats, departed to provide distant cover.[13] On 26 August 1914, the German light cruiser Magdeburg had run aground in the Gulf of Finland; the wreck was captured by the Russian navy, which found code books used by the German navy, along with navigational charts for the North Sea. These documents were then passed on to the Royal Navy. Room 40 began decrypting German signals, and on 14 December, intercepted messages relating to the plan to bombard Scarborough.[13] However, the exact details of the plan were unknown, and it was assumed that the High Seas Fleet would remain safely in port, as in the previous bombardment. Vice Admiral Beatty's four battlecruisers, supported by the 3rd Cruiser Squadron and the 1st Light Cruiser Squadron, along with the 2nd Battle Squadron's six dreadnoughts, were to ambush Hipper's battlecruisers.[14] During the night of 15 December, the main body of the High Seas Fleet encountered British destroyers. Fearing the prospect of a nighttime torpedo attack, Admiral Ingenohl ordered the ships to retreat.[14] Hipper was unaware of Ingenohl's reversal, and so he continued with the bombardment. Upon reaching the British coast, Hipper's battlecruisers split into two groups. Seydlitz, Moltke, and Blücher went north to shell Hartlepool, while Von der Tann and Derfflinger went south to shell Scarborough and Whitby.[15] During the bombardment of Hartlepool, Moltke was struck by a 6 in (15.2 cm) shell from a coastal battery,[7] which caused minor damage between decks, but no casualties.[15] Blücher was hit six times and Seydlitz three times by the coastal battery.[15] By 09:45 on the 16th, the two groups had reassembled, and they began to retreat eastward.[16] The High Seas Fleet's disposition on the morning of 16 December By this time, Beatty's battlecruisers were in position to block Hipper's chosen egress route, while other forces were en route to complete the encirclement. At 12:25, the light cruisers of the II Scouting Group began to pass through the British forces searching for Hipper.[17] One of the cruisers in the 2nd Light Cruiser Squadron spotted Stralsund and signaled a report to Beatty. At 12:30, Beatty turned his battlecruisers towards the German ships. Beatty presumed that the German cruisers were the advance screen for Hipper's ships, however those were some 50 km (31 mi) ahead.[17] The 2nd Light Cruiser Squadron, which had been screening for Beatty's ships, detached to pursue the German cruisers, but a misinterpreted signal from the British battlecruisers sent them back to their screening positions.[Note 4] This confusion allowed the German light cruisers to escape and alerted Hipper to the location of the British battlecruisers. The German battlecruisers wheeled to the northeast of the British forces and made good their escape.[17] Both the British and the Germans were disappointed that they failed to effectively engage their opponents. Admiral Ingenohl's reputation suffered greatly as a result of his timidity. The captain of the Moltke was furious; he stated that Ingenohl had turned back "because he was afraid of eleven British destroyers which could have been eliminated ... under the present leadership we will accomplish nothing."[18] The official German history criticized Ingenohl for failing to use his light forces to determine the size of the British fleet, stating: "he decided on a measure which not only seriously jeopardized his advance forces off the English coast but also deprived the German Fleet of a signal and certain victory."[18] Battle of Dogger Bank Main article: Battle of Dogger Bank (1915) SMS Moltke underway In early January 1915, it became known that British ships were conducting reconnaissance in the Dogger Bank area. Ingenohl was initially reluctant to destroy these forces, because the I Scouting Group was temporarily weakened while Von der Tann was in drydock for periodic maintenance. However, Konteradmiral Richard Eckermann, the Chief of Staff of the High Seas Fleet, insisted on the operation, and so Ingenohl relented and ordered Hipper to take his battlecruisers to the Dogger Bank.[19] On 23 January, Hipper sortied, with his flag in Seydlitz, followed by Moltke, Derfflinger, and Blücher, along with the light cruisers Graudenz, Rostock, Stralsund, and Kolberg and 19 torpedo boats from V Flotilla and II and XVIII Half-Flotillas. Graudenz and Stralsund were assigned to the forward screen, while Kolberg and Rostock were assigned to the starboard and port, respectively. Each light cruiser had a half-flotilla of torpedo boats attached.[19] Again, interception and decryption of German wireless signals played an important role. Although they were unaware of the exact plans, the cryptographers of Room 40 were able to deduce that Hipper would be conducting an operation in the Dogger Bank area.[19] To counter it, Beatty's 1st Battlecruiser Squadron, Rear Admiral Archibald Moore's 2nd Battlecruiser Squadron and Commodore William Goodenough's 2nd Light Cruiser Squadron were to rendezvous with Commodore Reginald Tyrwhitt's Harwich Force at 8:00 on 24 January, approximately 30 mi (48 km) north of the Dogger Bank.[19] At 08:14, Kolberg spotted the light cruiser Aurora and several destroyers from the Harwich Force.[20]Aurora challenged Kolberg with a search light, at which point Kolberg attacked Aurora and scored two hits. Aurora returned fire and scored two hits on Kolberg in retaliation. Hipper immediately turned his battlecruisers towards the gunfire, when, almost simultaneously, Stralsund spotted a large amount of smoke to the northwest of her position. This was identified as a number of large British warships steaming towards Hipper's ships.[20] Hipper turned south to flee, but was limited to 23 knots (43 km/h), which was the maximum speed of the older armored cruiser Blücher. The pursuing British battlecruisers were steaming at 27 knots (50 km/h), and quickly caught up to the German ships. At 09:52, Lion opened fire on Blücher from a range of approximately 20,000 yards (18,300 m); shortly thereafter, Queen Mary and Tiger began firing as well.[20] At 10:09, the British guns made their first hit on Blücher. Two minutes later, the German ships began returning fire, primarily concentrating on Lion, from a range of 18,000 yards (15,460 m). At 10:28, Lion was struck on the waterline, which tore a hole in the side of the ship and flooded a coal bunker.[21] At 10:30, New Zealand, the fourth ship in Beatty's line, came within range of Blücher and opened fire. By 10:35, the range had closed to 17,500 yards (16,000 m), at which point the entire German line was within the effective range of the British ships. Beatty ordered his battlecruisers to engage their German counterparts.[Note 5] However, confusion aboard Tiger led the captain to believe he was to fire on Seydlitz, which left Moltke able to fire without distraction.[21] At 10:40, one of Lion's 13.5 in (34 cm) shells struck Seydlitz causing nearly catastrophic damage that knocked out both of the rear turrets and killed 159 men.[22] Disaster was averted when the executive officer ordered the flooding of both magazines to avoid a flash fire that would have destroyed the ship.[Note 6] By this time, the German battlecruisers had zeroed in on Lion and began scoring repeated hits. At 11:01, an 11 in (28 cm) shell from Seydlitz struck Lion and knocked out two of her dynamos. At 11:18, Lion was hit by two 12 in (30 cm) shells from Derfflinger, one of which struck the waterline and penetrated the belt, allowing seawater to enter the port feed tank. This shell eventually crippled Lion by forcing the ship to turn off its engines due to seawater contamination.[22] By this time, Blücher was severely damaged after having been pounded by heavy shells. However, the chase ended when there were several reports of U-boats ahead of the British ships; Beatty quickly ordered evasive maneuvers, which allowed the German ships to increase the distance to their pursuers.[23] At this time, Lion's last operational dynamo failed, which dropped her speed to 15 knots. Beatty, in the stricken Lion, ordered the remaining battlecruisers to "Engage the enemy's rear," but signal confusion caused the ships to solely target Blücher, allowing Moltke, Seydlitz, and Derfflinger to escape.[24] By the time Beatty regained control over his ships, after having boarded Princess Royal, the German ships had too far a lead for the British to catch them; at 13:50, he broke off the chase.[25] Battle of the Gulf of Riga Main article: Battle of the Gulf of Riga On 3 August 1915, Moltke was transferred to the Baltic with I Reconnaissance Group (AG) to participate in the foray into the Riga Gulf. The intention was to destroy the Russian naval forces in the area, including the pre-dreadnought Slava, and to use the minelayer Deutschland to block the entrance to Moon Sound with naval mines. The German forces, under the command of Vice Admiral Hipper, included the four Nassau and four Helgoland battleships, the battlecruisers Moltke, Von der Tann, and Seydlitz, and a number of smaller craft.[26] On 8 August, the first attempt to clear the gulf was made; the old battleships Braunschweig and Elsaß kept Slava at bay while minesweepers cleared a path through the inner belt of mines. During this period, the rest of the German fleet remained in the Baltic and provided protection against other units of the Russian fleet. However, the approach of nightfall meant that Deutschland would be unable to mine the entrance to Moon Sound in time, and so the operation was broken off.[27] On 16 August, a second attempt was made to enter the gulf. The dreadnoughts Nassau and Posen, four light cruisers, and 31 torpedo boats breached the defenses to the gulf.[28] Nassau and Posen engaged in an artillery duel with Slava, resulting in three hits on the Russian ship that prompted her withdrawal. After three days, the Russian minefields had been cleared, and the flotilla entered the gulf on 19 August, but reports of Allied submarines in the area prompted a German withdrawal from the gulf the following day.[29] Throughout the operation, Moltke remained in the Baltic and provided cover for the assault into the Gulf of Riga. On the morning of the 19th, Moltke was torpedoed by the British E class submarine E1. The torpedo was not spotted until it was approximately 200 yards (183 m) away; without time to maneuver, the ship was struck in the bow torpedo room. The explosion damaged several torpedoes in the ship, but they did not detonate themselves. Eight men were killed, and 435 tonnes (480 short tons) of water entered the ship. The ship was repaired at Blohm & Voss in Hamburg, between 23 August and 20 September.[7] Bombardment of Yarmouth and Lowestoft Main article: Bombardment of Yarmouth and Lowestoft Moltke also took part in the bombardment of Yarmouth and Lowestoft on 24–25 April. Hipper was away on sick leave, so the German ships were under the command of Konteradmiral Friedrich Bödicker. The German battlecruisers Derfflinger, Lützow, Moltke, Seydlitz and Von der Tann left the Jade Estuary at 10:55 on 24 April, and were supported by a screening force of six light cruisers and two torpedo boat flotillas.[30] The heavy units of the High Seas Fleet sailed at 13:40, with the objective to provide distant support for Bödicker's ships. The British Admiralty was made aware of the German sortie through the interception of German wireless signals, and deployed the Grand Fleet at 15:50.[30] By 14:00, Bödicker's ships had reached a position off Norderney, at which point he turned his ships northward to avoid the Dutch observers on the island of Terschelling. At 15:38, Seydlitz struck a naval mine, which tore a 50-foot (15 m) hole in her hull, just abaft of the starboard broadside torpedo tube, allowing 1,400 short tons (1,250 long tons) of water to enter the ship.[30] Seydlitz turned back, with the screen of light cruisers, at a speed of 15 knots (28 km/h). The four remaining battlecruisers turned south immediately in the direction of Norderney to avoid further mine damage. By 16:00, Seydlitz was clear of imminent danger, so the ship stopped to allow Bödicker to disembark. The torpedo boat V28 brought Bödicker to Lützow.[31] At 04:50 on 25 April, the German battlecruisers were approaching Lowestoft when the light cruisers Rostock and Elbing, which had been covering the southern flank, spotted the light cruisers and destroyers of Commodore Tyrwhitt's Harwich Force.[31] Bödicker refused to be distracted by the British ships, and instead trained his ships' guns on Lowestoft. The German battlecruisers destroyed two 6 in (15 cm) shore batteries and inflicted other damage to the town. In the process, a single 6 in shell from one of the shore batteries struck Moltke, but the ship sustained no significant damage.[7] At 05:20, the German raiders turned north, towards Yarmouth, which they reached by 05:42. The visibility was so poor that the German ships fired one salvo each, with the exception of Derfflinger, which fired fourteen rounds from her main battery. The German ships turned back south, and at 05:47 encountered for the second time the Harwich Force, which had by then been engaged by the six light cruisers of the screening force. Bödicker's ships opened fire from a range of 13,000 yards (12,000 m).[32] Tyrwhitt immediately turned his ships around and fled south, but not before the cruiser Conquest sustained severe damage. Due to reports of British submarines and torpedo attacks, Bödicker broke off the chase and turned back east towards the High Seas Fleet. At this point, Scheer, who had been warned of the Grand Fleet's sortie from Scapa Flow, turned back towards Germany.[32] Battle of Jutland Main article: Battle of Jutland Moltke, and the rest of Hipper's battlecruisers in the I Scouting Group, lay anchored in the outer Jade Roads on the night of 30 May 1916. The following morning, at 02:00 CET,[Note 7] the ships slowly steamed out towards the Skagerrak at a speed of 16 knots (30 km/h).[33] Moltke was the fourth ship in the line of five, ahead of Von der Tann, and to the rear of Seydlitz.[33] The II Scouting Group, consisting of the light cruisers Frankfurt, Rear Admiral Bödicker's flagship, Wiesbaden, Pillau, and Elbing, and 30 torpedo boats of the II, VI, and IX Flotillas, accompanied Hipper's battlecruisers.[33] An hour and a half later, the High Seas Fleet under the command of Admiral Scheer left the Jade; the force was composed of 16 dreadnoughts.[Note 8] The High Seas Fleet was accompanied by the IV Scouting Group, composed of the light cruisers Stettin, München, Hamburg, Frauenlob, and Stuttgart, and 31 torpedo boats of the I, III, V, and VII Flotillas, led by the light cruiser Rostock. The six pre-dreadnoughts of the II Battle Squadron had departed from the Elbe roads at 02:45, and rendezvoused with the battle fleet at 5:00.[33] Shortly before 16:00, Hipper's force encountered Vice Admiral Beatty's battlecruiser squadron. The German ships were the first to open fire, at a range of approximately 15,000 yards (14,000 m).[34] When the British ships began returning fire, confusion amongst the British battlecruisers resulted in Moltke being engaged by both New Zealand and Tiger.[Note 9] The British rangefinders had misread the range to their German targets, and so the first salvos fired by the British ships fell a mile past the German battlecruisers. At 16:52, Moltke hit Tiger with two main gun shells, but neither of these hits caused any significant damage. Moltke then fired a further four shells, two of which hit simultaneously on the midships and after turrets, knocking both out for a significant period of the battle.[35] The destruction of Indefatigable Approximately 15 minutes later, the British battlecruiser Indefatigable was suddenly destroyed by Von der Tann. Shortly thereafter, Moltke fired four torpedoes at Queen Mary at a range between 11,500–10,400 yards (10,500–9,500 m).[36] This caused the British line to fall into disarray, as the torpedoes were thought to have been fired by U-boats. At this point, Hipper's battlecruisers had come into range of the V Battle Squadron, composed of the new Queen Elizabeth-class battleships, which mounted powerful 15 in (38 cm) guns. At 17:06, Barham opened fire on Von der Tann. She was joined a few minutes later by Valiant, Malaya, and Warspite; the ships concentrated their fire on Von der Tann and Moltke.[37] At 17:16, one of the 15 in shells from the fast battleships struck Moltke, where it pierced a coal bunker, tore into a casemate deck, and ignited ammunition stored therein. The explosion burned the ammunition hoist down to the magazine.[38] Von der Tann and Moltke changed their speed and direction, which threw off the aim of the V Battle Squadron and earned the battered ships a short respite.[38] While Moltke and Von der Tann were drawing the fire of the V Battle Squadron battleships, Seydlitz and Derfflinger were able to concentrate their fire on the British battlecruisers; between 17:25 and 17:30, at least five shells from Seydlitz and Derfflinger struck Queen Mary, causing a catastrophic explosion that destroyed the ship.[39] Moltke's commander, Kapitän zur See von Karpf, remarked that "The enemy's salvos lie well and close; their salvos are fired in rapid succession, the fire discipline is excellent!"[40] By 19:30, the High Seas Fleet, which was by that point pursuing the British battlecruisers, had not yet encountered the Grand Fleet. Scheer had been considering retiring his forces before darkness exposed his ships to torpedo boat attack.[41] However, he had not yet made a decision when his leading battleships encountered the main body of the Grand Fleet. This development made it impossible for Scheer to retreat, for doing so would have sacrificed the slower pre-dreadnought battleships of the II Battle Squadron, while using his dreadnoughts and battlecruisers to cover their retreat would have subjected his strongest ships to overwhelming British fire.[42] Instead, Scheer ordered his ships to turn 16 points to starboard, which would bring the pre-dreadnoughts to the relative safety of the disengaged side of the German battle line.[43] Moltke and the other battlecruisers[Note 10] followed the move, which put them astern of König.[44] Hipper's badly battered ships gained a temporary moment of respite, and uncertainty over the exact location and course of Scheer's ships led Admiral Jellicoe to turn his ships eastward, towards what he thought was the likely path of the German retreat.[45] The German fleet was instead sailing west, but Scheer ordered a second 16-point turn, which reversed course and pointed his ships at the center of the British fleet.[46] The German fleet came under intense fire from the British line, and Scheer sent Moltke, Von der Tann, Seydlitz, and Derfflinger at high speed towards the British fleet, in an attempt to disrupt their formation and gain time for his main force to retreat.[47] By 20:17, the German battlecruisers had closed to within 7,700 yards (7,040 m) of Colossus, at which point Scheer directed the ships to engage the lead ship of the British line.[48] However, three minutes later, the German battlecruisers turned in retreat, covered by a torpedo boat attack.[49] A pause in the battle at dusk allowed Moltke and the other German battlecruisers to cut away wreckage that interfered with the main guns, extinguish fires, repair the fire control and signal equipment, and ready the searchlights for nighttime action. During this period, the German fleet reorganized into a well-ordered formation in reverse order, when the German light forces encountered the British screen shortly after 21:00. The renewed gunfire gained Beatty's attention, so he turned his battlecruisers westward. At 21:09, he sighted the German battlecruisers, and drew to within 8,500 yards (7,800 m) before opening fire at 20:20.[50] The attack from the British battlecruisers completely surprised Hipper, who had been in the process of boarding Moltke from the torpedo boat G39. The German ships returned fire with every gun available, and at 21:32 hit both Lion and Princess Royal in the darkness.[51] The maneuvering of the German battlecruisers forced the leading I Battle Squadron to turn westward to avoid collision. This brought the pre-dreadnoughts of the II Battle Squadron directly behind the battlecruisers, and prevented the British ships from pursuing the German battlecruisers when they turned southward. The British battlecruisers opened fire on the old battleships; the German ships turned southwest to bring all of their guns to bear against the British ships.[51] By 22:15, Hipper was finally able to transfer to Moltke, and then ordered his ships to steam at 20 knots (37 km/h) towards the head of the German line.[52] However, only Moltke and Seydlitz were in condition to comply; Derfflinger and Von der Tann could make at most 18 knots, and so these ships lagged behind. Moltke and Seydlitz were in the process of steaming to the front of the line when the ships passed close to Stettin, which forced the ship to drastically slow down to avoid collision. This forced Frauenlob, Stuttgart, and München to turn to port, which led them into contact with the 2nd Light Cruiser Squadron; at a range of 800 yards (730 m), the cruisers on both sides pummeled each other. Rear Admiral Ludwig von Reuter decided to attempt to lure the British cruisers towards Moltke and Seydlitz. However, nearly simultaneously, the heavily damaged British cruisers broke off the attack.[53] As the light cruisers were disengaging, a torpedo fired by Southampton struck Frauenlob, and the ship exploded.[54] The German formation fell into disarray, and in the confusion, Seydlitz lost sight of Moltke. Seydlitz was no longer able to keep up with Moltke's 22 knots (41 km/h), and so detached herself to proceed to the Horns Reef lighthouse independently.[54] By 23:30 on her own, Moltke encountered four British dreadnoughts, from the rear division of the 2nd Battle Squadron. Moltke's commander Kapitän von Karpf ordered the ship to swing away, hoping he had not been detected. The British ships in fact had seen Moltke, but had decided to not to open fire in order to not reveal their location to the entire German fleet.[55] At 23:55, and again at 00:20, Kapitän von Karpf tried to find a path through the British fleet, but both times was unable to do so. It was not until 01:00, after having steamed far ahead of the Grand Fleet, that Moltke was able to made good her escape.[55] The severely damaged Seydlitz returning to port after the battle Close to the end of the battle, at 03:55, Hipper transmitted a report to Admiral Scheer informing him of the tremendous damage his ships had suffered. By that time, Derfflinger and Von der Tann each had only two guns in operation, Moltke was flooded with 1,000 tons of water, and Seydlitz was severely damaged.[56] Hipper reported: "I Scouting Group was therefore no longer of any value for a serious engagement, and was consequently directed to return to harbour by the Commander-in-Chief, while he himself determined to await developments off Horns Reef with the battlefleet."[56] During the course of the battle, Moltke had hit Tiger 13 times, and was hit herself 4 times, all by 15 in (38 cm) shells. The starboard No. 5 15 cm gun was struck by one of the 15 in shells and put out of action for the remainder of the battle. The ship suffered 16 dead and 20 wounded, the majority of which were due to the hit on the 15 cm gun. Flooding and counter-flooding efforts caused 1,000 tons of water to enter the ship.[57] Later operations During the fleet advance on 18–19 August, the I Scouting Group was to bombard the coastal town of Sunderland in an attempt to draw out and destroy Beatty's battlecruisers. As Moltke was one of only two remaining German battlecruisers still in fighting condition in the Group (Von der Tann being the other), three dreadnoughts were assigned to the Group for the operation: Markgraf, Großer Kurfürst, and the newly commissioned Bayern. Admiral Scheer and the rest of the High Seas Fleet, with 15 dreadnoughts of its own, would trail behind and provide cover.[58] The British were aware of the German plans and sortied the Grand Fleet to meet them. By 14:35, Scheer had been warned of the Grand Fleet's approach and, unwilling to engage the whole of the Grand Fleet just 11 weeks after the decidedly close call at Jutland, turned his forces around and retreated to German ports.[59] In September 1917, KzS von Karpf left Moltke; KzS Gygas assumed command of the ship. Between September and October 1917, the ship took part in Operation Albion supporting the German invasion of the Russian islands of Ösel, Dagö, and Moon (in present-day Estonia). Following the successful operation in the Baltic, Moltke was detached to support the II Reconnaissance Group (II AG), but did not actively participate in the Second Battle of Heligoland Bight.[57] Late 1917 saw the High Seas Fleet beginning to conduct anti-convoy raids in the North Sea between Britain and Norway. In October and December 1917, two British convoys to Norway were intercepted and destroyed by German cruisers and destroyers, prompting Beatty, now the Commander in Chief of the Grand Fleet, to detach several battleships and battlecruisers to protect convoys.[60] This presented to Admiral Scheer the opportunity for which he had been waiting the entire war: the chance to isolate and eliminate a portion of the Grand Fleet.[61] At 05:00 on 23 April 1918, the High Seas Fleet left harbor with the intention of intercepting one of the heavily escorted convoys. Wireless radio traffic was kept to a minimum to prevent the British from learning of the operation.[61] At 05:10 on 24 April, Moltke suffered machinery failure: the starboard propeller had fallen off the shaft, and before the turbine could be stopped, a gear wheel was destroyed.[61] The destroyed wheel flung pieces of steel into an auxiliary condenser, which flooded the engine room and stopped the operation of the center and starboard engines. Saltwater entered the boilers, reducing the ship's speed to a mere four knots; by 08:45, the captain of Moltke reported to Scheer that his ship was "out of control",[61] and that the ship would need to be towed. At 09:38, the cruiser Strassburg attempted to take the ship under tow, but was unable to do so. At 10:13, the dreadnought Oldenburg was detached from the battle fleet to tow Moltke back to port.[62] At 14:10, the convoy had still not yet been located, and so Scheer turned the High Seas Fleet back towards German waters. By 17:10, Moltke's engines had been repaired, and the ship was able to steam at a speed of 17 knots.[62] At 19:37, the British submarine E42 spotted the ship and fired a torpedo into Moltke. The ship took in 1,800 tons of water, but was able to reach harbor under her own power.[63] Repairs were carried out in Wilhelmshaven in the Imperial Dockyard, between 30 April and 9 September 1918.[62] Following repairs, Moltke took part in training operations in the Baltic from 19 September to 3 October. Starting on 1 November, the ship served as the I Scouting Group flagship for Rear Admiral von Reuter,[62] after the battlecruiser Hindenburg had gone into dry dock for repairs.[64] Fate Seydlitz leading the German battlecruisers into internment; Moltke is the second ship in the line Moltke was to have taken part in what would have amounted to the "death ride" of the High Seas Fleet shortly before the end of World War I. The bulk of the High Seas Fleet was to have sortied from their base in Wilhelmshaven to engage the British Grand Fleet; Scheer—by now the Großadmiral of the fleet—intended to inflict as much damage as possible on the British navy, in order to retain a better bargaining position for Germany, whatever the cost to the fleet.[65] However, while the fleet was consolidating in Wilhelmshaven, war-weary sailors began deserting en masse. As Von der Tann and Derfflinger passed through the locks that separated Wilhelmshaven's inner harbour and roadstead, some 300 men from both ships climbed over the side and disappeared ashore.[66] On 24 October 1918, the order was given to sail from Wilhelmshaven. Starting on the night of 29 October, sailors on several battleships mutinied; three ships from the III Squadron refused to weigh anchors, and acts of sabotage were committed on board the battleships Thüringen and Helgoland. The order to sail was rescinded in the face of this open revolt. In early November 1918, the German Revolution began; it led to the Armistice that ended the war and toppled the monarchy.[67] The vessel was surrendered with the rest of the High Seas Fleet on 24 November 1918 and interned at Scapa Flow, under the command of Kapitän-Leutnant Wollante.[68] Believing that the Treaty of Versailles had been signed and his fleet was about to be seized by the British, Rear Admiral von Reuter ordered the scuttling of the High Seas Fleet on 21 June 1919, while the British Grand Fleet was away on exercises. The ship sank in two hours and fifteen minutes.[69] Moltke was raised in 1927 and scrapped at Rosyth in 1929.[70]

Gold This article is about the metal. For the color, see Gold (color). For other uses, see Gold (disambiguation). Gold (pronounced /'go?ld/) is a chemical element with the symbol Au (Latin: aurum, "shining dawn") and an atomic number of 79. It has been a highly sought-after precious metal for coinage, jewelry, and other arts since the beginning of recorded history. The metal occurs as nuggets or grains in rocks, in veins and in alluvial deposits. Gold is dense, soft, shiny and the most malleable and ductile pure metal known. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Gold is one of the coinage metals and has served as a symbol of wealth and a store of value throughout history. Gold standards have provided a basis for monetary policies. It also has been linked to a variety of symbolisms and ideologies. A total of 161,000 tonnes of gold have been mined in human history, as of 2009.[1] This is roughly equivalent to 5.175 billion troy ounces or, in terms of volume, about 8,333 cubic metres, and could be valued at just under six trillion United States dollars at early March 2010 prices. Although primarily used as a store of value, gold has many modern industrial uses including dentistry and electronics. Gold has traditionally found use because of its good resistance to oxidative corrosion and excellent quality as a conductor of electricity. Chemically, gold is a transition metal and can form trivalent and univalent cations in solutions. Compared with other metals, pure gold is chemically least reactive, but it is attacked by aqua regia (a mixture of acids), forming chloroauric acid, but not by the individual acids, and by alkaline solutions of cyanide. Gold dissolves in mercury, forming amalgam alloys, but does not react with it. Gold is insoluble in nitric acid, which dissolves silver and base metals. This property is exploited in the gold refining technique known as "inquartation and parting". Nitric acid has long been used to confirm the presence of gold in items, and this is the origin of the colloquial term "acid test", referring to a gold standard test for genuine value. Characteristics Native gold nuggets Gold nuggets found in Arizona Gold is the most malleable and ductile of all metals; a single gram can be beaten into a sheet of 1 square meter, or an ounce into 300 square feet. Gold leaf can be beaten thin enough to become translucent. The transmitted light appears greenish blue, because gold strongly reflects yellow and red.[2] Such semi-transparent sheets also strongly reflect infrared light, making them useful as infrared (radiant heat) shields in visors of heat-resistant suits, and in sun-visors for spacesuits.[3] Gold readily creates alloys with many other metals. These alloys can be produced to modify the hardness and other metallurgical properties, to control melting point or to create exotic colors (see below). Gold is a good conductor of heat and electricity and reflects infrared radiation strongly. Chemically, it is unaffected by air, moisture and most corrosive reagents, and is therefore well-suited for use in coins and jewelry and as a protective coating on other, more reactive, metals. However, it is not chemically inert. Common oxidation states of gold include +1 (gold(I) or aurous compounds) and +3 (gold(III) or auric compounds). Gold ions in solution are readily reduced and precipitated out as gold metal by adding any other metal as the reducing agent. The added metal is oxidized and dissolves allowing the gold to be displaced from solution and be recovered as a solid precipitate. High quality pure metallic gold is tasteless; in keeping with its resistance to corrosion (it is metal ions which confer taste to metals). In addition, gold is very dense, a cubic meter weighing 19,300 kg. By comparison, the density of lead is 11,340 kg/m3, and that of the densest element, osmium, is 22,610 kg/m3. Color Different colors of Ag-Au-Cu alloys Whereas most other pure metals are gray or silvery white, gold is yellow. This color is determined by the density of loosely bound (valence) electrons; those electrons oscillate as a collective "plasma" medium described in terms of a quasiparticle called plasmon. The frequency of these oscillations lies in the ultraviolet range for most metals, but it falls into the visible range for gold due to subtle relativistic effects that affect the orbitals around gold atoms.[4][5] Common colored gold alloys such as rose gold can be created by the addition of various amounts of copper and silver, as indicated in the triangular diagram on the right. Alloys containing palladium or nickel are also important in commercial jewelry as these produce white gold alloys. Less commonly, addition of manganese, aluminium, iron, indium and other elements can produce more unusual colors of gold for various applications.[6] Isotopes Main article: Isotopes of gold Gold has only one stable isotope, 197Au, which is also its only naturally occurring isotope. 36 radioisotopes have been synthesized ranging in atomic mass from 169 to 205. The most stable of these is 195Au with a half-life of 186.1 days. 195Au is also the only gold isotope to decay by electron capture. The least stable is 171Au, which decays by proton emission with a half-life of 30 µs. Most of gold's radioisotopes with atomic masses below 197 decay by some combination of proton emission, a decay, and ß+ decay. The exceptions are 195Au, which decays by electron capture, and 196Au, which has a minor ß- decay path. All of gold's radioisotopes with atomic masses above 197 decay by ß- decay.[7] At least 32 nuclear isomers have also been characterized, ranging in atomic mass from 170 to 200. Within that range, only 178Au, 180Au, 181Au, 182Au, and 188Au do not have isomers. Gold's most stable isomer is 198 m2Au with a half-life of 2.27 days. Gold's least stable isomer is 177 m2Au with a half-life of only 7 ns. 184 m1Au has three decay paths: ß+ decay, isomeric transition, and alpha decay. No other isomer or isotope of gold has three decay paths.[7] Use and applications Monetary exchange Gold has been widely used throughout the world as a vehicle for monetary exchange, either by issuance and recognition of gold coins or other bare metal quantities, or through gold-convertible paper instruments by establishing gold standards in which the total value of issued money is represented in a store of gold reserves. However, the amount of gold in the world is finite and production has not grown in relation to the world's economies. Today, gold mining output is declining.[8] With the sharp growth of economies in the 20th century, and increasing foreign exchange, the world's gold reserves and their trading market have become a small fraction of all markets and fixed exchange rates of currencies to gold became unsustainable. At the beginning of World War I the warring nations moved to a fractional gold standard, inflating their currencies to finance the war effort. After World War II gold was replaced by a system of convertible currency following the Bretton Woods system. Gold standards and the direct convertibility of currencies to gold have been abandoned by world governments, being replaced by fiat currency in their stead. Switzerland was the last country to tie its currency to gold; it backed 40% of its value until the Swiss joined the International Monetary Fund in 1999.[9] Pure gold is too soft for day-to-day monetary use and is typically hardened by alloying with copper, silver or other base metals. The gold content of alloys is measured in carats (k). Pure gold is designated as 24k. Gold coins intended for circulation from 1526 into the 1930s were typically a standard 22k alloy called crown gold, for hardness. Investment Many holders of gold store it in form of bullion coins or bars as a hedge against inflation or other economic disruptions. However, some economists do not believe gold serves as a hedge against inflation or currency depreciation.[10] The ISO 4217 currency code of gold is XAU. Modern bullion coins for investment or collector purposes do not require good mechanical wear properties; they are typically fine gold at 24k, although the American Gold Eagle, the British gold sovereign, and the South African Krugerrand continue to be minted in 22k metal in historical tradition. The special issue Canadian Gold Maple Leaf coin contains the highest purity gold of any bullion coin, at 99.999% or .99999 finess, while the popular issue Canadian Gold Maple Leaf coin has a purity of 99.99%. Several other 99.99% pure gold coins are available. The Australian Gold Kangaroos was first coined in 1986 as the Australian Gold Nugget. Its kangaroo theme appeared in 1989. In addition, there are several coins of the Australian Lunar Calendar series, and the Austrian Philharmonic. In 2006, the United States Mint began production of the American Buffalo gold bullion coin with a purity of 99.99%. Jewelry Moche gold necklace depicting feline heads. Larco Museum Collection. Lima-Peru Because of the softness of pure (24k) gold, it is usually alloyed with base metals for use in jewelry, altering its hardness and ductility, melting point, color and other properties. Alloys with lower caratage, typically 22k, 18k, 14k or 10k, contain higher percentages of copper, or other base metals or silver or palladium in the alloy. Copper is the most commonly used base metal, yielding a redder color. Eighteen carat gold containing 25% copper is found in antique and Russian jewelry and has a distinct, though not dominant, copper cast, creating rose gold. Fourteen carat gold-copper alloy is nearly identical in color to certain bronze alloys, and both may be used to produce police, as well as other, badges. Blue gold can be made by alloying with iron and purple gold can be made by alloying with aluminium, although rarely done except in specialized jewelry. Blue gold is more brittle and therefore more difficult to work with when making jewelry. Fourteen and eighteen carat gold alloys with silver alone appear greenish-yellow and are referred to as green gold. White gold alloys can be made with palladium or nickel. White 18 carat gold containing 17.3% nickel, 5.5% zinc and 2.2% copper is silver in appearance. Nickel is toxic, however, and its release from nickel white gold is controlled by legislation in Europe. Alternative white gold alloys are available based on palladium, silver and other white metals (World Gold Council), but the palladium alloys are more expensive than those using nickel. High-carat white gold alloys are far more resistant to corrosion than are either pure silver or sterling silver. The Japanese craft of Mokume-gane exploits the color contrasts between laminated colored gold alloys to produce decorative wood-grain effects. Medicine This section is in a list format that may be better presented using prose. You can help by converting this section to prose, if appropriate. Editing help is available. (January 2009) • In medieval times, gold was often seen as beneficial for the health, in the belief that something that rare and beautiful could not be anything but healthy. Even some modern esotericists and forms of alternative medicine assign metallic gold a healing power.[11] Some gold salts do have anti-inflammatory properties and are used as pharmaceuticals in the treatment of arthritis and other similar conditions.[12] However, only salts and radioisotopes of gold are of pharmacological value, as elemental (metallic) gold is inert to all chemicals it encounters inside the body. • In modern times, injectable gold has been proven to help to reduce the pain and swelling of rheumatoid arthritis and tuberculosis.[12][13] • Dentistry. Gold alloys are used in restorative dentistry, especially in tooth restorations, such as crowns and permanent bridges. The gold alloys' slight malleability facilitates the creation of a superior molar mating surface with other teeth and produces results that are generally more satisfactory than those produced by the creation of porcelain crowns. The use of gold crowns in more prominent teeth such as incisors is favored in some cultures and discouraged in others. • Colloidal gold preparations (suspensions of gold nanoparticles) in water are intensely red-colored, and can be made with tightly controlled particle sizes up to a few tens of nanometers across by reduction of gold chloride with citrate or ascorbate ions. Colloidal gold is used in research applications in medicine, biology and materials science. The technique of immunogold labeling exploits the ability of the gold particles to adsorb protein molecules onto their surfaces. Colloidal gold particles coated with specific antibodies can be used as probes for the presence and position of antigens on the surfaces of cells (Faulk and Taylor 1979). In ultrathin sections of tissues viewed by electron microscopy, the immunogold labels appear as extremely dense round spots at the position of the antigen (Roth et al. 1980). Colloidal gold is also the form of gold used as gold paint on ceramics prior to firing. • Gold, or alloys of gold and palladium, are applied as conductive coating to biological specimens and other non-conducting materials such as plastics and glass to be viewed in a scanning electron microscope. The coating, which is usually applied by sputtering with an argon plasma, has a triple role in this application. Gold's very high electrical conductivity drains electrical charge to earth, and its very high density provides stopping power for electrons in the electron beam, helping to limit the depth to which the electron beam penetrates the specimen. This improves definition of the position and topography of the specimen surface and increases the spatial resolution of the image. Gold also produces a high output of secondary electrons when irradiated by an electron beam, and these low-energy electrons are the most commonly used signal source used in the scanning electron microscope. • The isotope gold-198, (half-life: 2.7 days) is used in some cancer treatments and for treating other diseases.[14] Food and drink • Gold can be used in food and has the E Number 175.[15] • Gold leaf, flake or dust is used on and in some gourmet foods, notably sweets and drinks as decorative ingredient.[16] Gold flake was used by the nobility in Medieval Europe as a decoration in food and drinks, in the form of leaf, flakes or dust, either to demonstrate the host's wealth or in the belief that something that valuable and rare must be beneficial for one's health. Gold foil along with silver is sometimes used on the South Asian sweets including Burfi.[17] • Goldwasser (English: Goldwater) is a traditional herbal liqueur produced in Gdansk, Poland, and Schwabach, Germany, and contains flakes of gold leaf. There are also some expensive (~$1000) cocktails which contain flakes of gold leaf.[18] However, since metallic gold is inert to all body chemistry, it adds no taste nor has it any other nutritional effect and leaves the body unaltered.[19] Industry The 220 kg gold brick displayed in Chinkuashi Gold Museum, Taiwan, Republic of China The world's largest gold bar weighs 250 kg. Toi museum, Japan. A gold nugget of 5 mm in diameter (bottom) can be expanded through hammering into a gold foil of about 0.5 square meter. Toi museum, Japan. • Gold solder is used for joining the components of gold jewelry by high-temperature hard soldering or brazing. If the work is to be of hallmarking quality, gold solder must match the carat weight of the work, and alloy formulas are manufactured in most industry-standard carat weights to color match yellow and white gold. Gold solder is usually made in at least three melting-point ranges referred to as Easy, Medium and Hard. By using the hard, high-melting point solder first, followed by solders with progressively lower melting points, goldsmiths can assemble complex items with several separate soldered joints. • Gold can be made into thread and used in embroidery. • Gold is ductile and malleable, meaning it can be drawn into very thin wire and can be beaten into very thin sheets known as gold leaf. • Gold produces a deep, intense red color when used as a coloring agent in cranberry glass. • In photography, gold toners are used to shift the color of silver bromide black and white prints towards brown or blue tones, or to increase their stability. Used on sepia-toned prints, gold toners produce red tones. Kodak published formulas for several types of gold toners, which use gold as the chloride (Kodak, 2006). • As gold is a good reflector of electromagnetic radiation such as infrared and visible light as well as radio waves, it is used for the protective coatings on many artificial satellites, in infrared protective faceplates in thermal protection suits and astronauts' helmets and in electronic warfare planes like the EA-6B Prowler. • Gold is used as the reflective layer on some high-end CDs. • Automobiles may use gold for heat dissipation. McLaren uses gold foil in the engine compartment of its F1 model.[20] • Gold can be manufactured so thin that it appears transparent. It is used in some aircraft cockpit windows for de-icing or anti-icing by passing electricity through it. The heat produced by the resistance of the gold is enough to deter ice from forming.[21] Electronics • The concentration of free electrons in gold metal is 5.90×1022 cm-3. Gold is highly conductive to electricity, and has been used for electrical wiring in some high-energy applications (silver is even more conductive per volume, but gold has the advantage of corrosion resistance). For example, gold electrical wires were used during some of the Manhattan Project's atomic experiments, but large high current silver wires were used in the calutron isotope separator magnets in the project. • Though gold is attacked by free chlorine, its good conductivity and general resistance to oxidation and corrosion in other environments (including resistance to non-chlorinated acids) has led to its widespread industrial use in the electronic era as a thin layer coating electrical connectors of all kinds, thereby ensuring good connection. For example, gold is used in the connectors of the more expensive electronics cables, such as audio, video and USB cables. The benefit of using gold over other connector metals such as tin in these applications is highly debated. Gold connectors are often criticized by audio-visual experts as unnecessary for most consumers and seen as simply a marketing ploy. However, the use of gold in other applications in electronic sliding contacts in highly humid or corrosive atmospheres, and in use for contacts with a very high failure cost (certain computers, communications equipment, spacecraft, jet aircraft engines) remains very common, and is unlikely to be replaced in the near future by any other metal. • Besides sliding electrical contacts, gold is also used in electrical contacts because of its resistance to corrosion, electrical conductivity, ductility and lack of toxicity.[22] Switch contacts are generally subjected to more intense corrosion stress than are sliding contacts. • Fine gold wires are used to connect semiconductor devices to their packages through a process known as wire bonding. Chemistry Gold is attacked by and dissolves in alkaline solutions of potassium or sodium cyanide, and gold cyanide is the electrolyte used in commercial electroplating of gold onto base metals and electroforming. Gold chloride (chloroauric acid) solutions are used to make colloidal gold by reduction with citrate or ascorbate ions. Gold chloride and gold oxide are used to make highly valued cranberry or red-colored glass, which, like colloidal gold suspensions, contains evenly sized spherical gold nanoparticles.[23] History The Turin Papyrus Map Funerary mask of Tutankhamun Jason returns with the golden fleece on an Apulian red-figure calyx krater, ca. 340–330 BC. Gold has been known and used by artisans since the Chalcolithic. Gold artifacts in the Balkans appear from the 4th millennium BC, such as that found in the Varna Necropolis. Gold artifacts such as the golden hats and the Nebra disk appeared in Central Europe from the 2nd millennium BC Bronze Age. Egyptian hieroglyphs from as early as 2600 BC describe gold, which king Tushratta of the Mitanni claimed was "more plentiful than dirt" in Egypt.[24] Egypt and especially Nubia had the resources to make them major gold-producing areas for much of history. The earliest known map is known as the Turin Papyrus Map and shows the plan of a gold mine in Nubia together with indications of the local geology. The primitive working methods are described by Strabo and included fire-setting. Large mines also were present across the Red Sea in what is now Saudi Arabia. The legend of the golden fleece may refer to the use of fleeces to trap gold dust from placer deposits in the ancient world. Gold is mentioned frequently in the Old Testament, starting with Genesis 2:11 (at Havilah) and is included with the gifts of the magi in the first chapters of Matthew New Testament. The Book of Revelation 21:21 describes the city of New Jerusalem as having streets "made of pure gold, clear as crystal". The south-east corner of the Black Sea was famed for its gold. Exploitation is said to date from the time of Midas, and this gold was important in the establishment of what is probably the world's earliest coinage in Lydia around 610 BC.[25] From the 6th or 5th century BC, the Chu (state) circulated the Ying Yuan, one kind of square gold coin. The Romans developed new methods for extracting gold on a large scale using hydraulic mining methods, especially in Spain from 25 BC onwards and in Romania from 150 AD onwards. One of their largest mines was at Las Medulas in León (Spain), where seven long aqueducts enabled them to sluice most of a large alluvial deposit. The mines at Rosia Montana in Transylvania were also very large, and until very recently, still mined by opencast methods. They also exploited smaller deposits in Britain, such as placer and hard-rock deposits at Dolaucothi. The various methods they used are well described by Pliny the Elder in his encyclopedia Naturalis Historia written towards the end of the first century AD. The Mali Empire in Africa was famed throughout the old world for its large amounts of gold. Mansa Musa, ruler of the empire (1312–1337) became famous throughout the old world for his great hajj to Mecca in 1324. When he passed through Cairo in July 1324, he was reportedly accompanied by a camel train that included thousands of people and nearly a hundred camels. He gave away so much gold that it depressed the price in Egypt for over a decade.[26] A contemporary Arab historian remarked: “ Gold was at a high price in Egypt until they came in that year. The mithqal did not go below 25 dirhams and was generally above, but from that time its value fell and it cheapened in price and has remained cheap till now. The mithqal does not exceed 22 dirhams or less. This has been the state of affairs for about twelve years until this day by reason of the large amount of gold which they brought into Egypt and spent there [...] ” —Chihab Al-Umari[27] The European exploration of the Americas was fueled in no small part by reports of the gold ornaments displayed in great profusion by Native American peoples, especially in Central America, Peru, Ecuador and Colombia. The Aztecs regarded gold as literally the product of the gods, calling it "god excrement" (teocuitlatl in Nahuatl).[28] Although the price of some platinum group metals can be much higher, gold has long been considered the most desirable of precious metals, and its value has been used as the standard for many currencies (known as the gold standard) in history. Gold has been used as a symbol for purity, value, royalty, and particularly roles that combine these properties. Gold as a sign of wealth and prestige was made fun of by Thomas More in his treatise Utopia. On that imaginary island, gold is so abundant that it is used to make chains for slaves, tableware and lavatory-seats. When ambassadors from other countries arrive, dressed in ostentatious gold jewels and badges, the Utopians mistake them for menial servants, paying homage instead to the most modestly dressed of their party. There is an age-old tradition of biting gold to test its authenticity. Although this is certainly not a professional way of examining gold, the bite test should score the gold because gold is a soft metal, as indicated by its score on the Mohs' scale of mineral hardness. The purer the gold the easier it should be to mark it. Painted lead can cheat this test because lead is softer than gold (and may invite a small risk of lead poisoning if sufficient lead is absorbed by the biting). Gold in antiquity was relatively easy to obtain geologically; however, 75% of all gold ever produced has been extracted since 1910.[29] It has been estimated that all gold ever refined would form a single cube 20 m (66 ft) on a side (equivalent to 8000 m3).[29] One main goal of the alchemists was to produce gold from other substances, such as lead — presumably by the interaction with a mythical substance called the philosopher's stone. Although they never succeeded in this attempt, the alchemists promoted an interest in what can be done with substances, and this laid a foundation for today's chemistry. Their symbol for gold was the circle with a point at its center (?), which was also the astrological symbol and the ancient Chinese character for the Sun. For modern creation of artificial gold by neutron capture, see gold synthesis. During the 19th century, gold rushes occurred whenever large gold deposits were discovered. The first documented discovery of gold in the United States was at the Reed Gold Mine near Georgeville, North Carolina in 1803.[30] The first major gold strike in the United States occurred in a small north Georgia town called Dahlonega.[31] Further gold rushes occurred in California, Colorado, the Black Hills, Otago, Australia, Witwatersrand, and the Klondike. Because of its historically high value, much of the gold mined throughout history is still in circulation in one form or another. Occurrence Gold ore This 156-ounce (4.85 kg) nugget was found by an individual prospector in the Southern California Desert using a metal detector. Gold's atomic number of 79 makes it one of the higher atomic number elements which occur naturally. Like all elements with atomic numbers larger than iron, gold is thought to have been formed from a supernova nucleosynthesis process. Their explosions scattered metal-containing dusts (including heavy elements like gold) into the region of space in which they later condensed into our solar system and the Earth. On Earth, whenever elemental gold occurs, it appears most often as a metal solid solution of gold with silver, i.e. a gold silver alloy. Such alloys usually have a silver content of 8–10%. Electrum is elemental gold with more than 20% silver. Electrum's color runs from golden silvery to silvery, dependent upon the silver content. The more silver, the lower the specific gravity. Relative sizes of a an 860kg rock ore, and the 30g of gold that can be extracted from it. Toi gold mine, Japan. Gold left behind after pyrite cube dissolved away. Gold is found in ores made up of rock with very small or microscopic particles of gold. This gold ore is often found together with quartz or sulfide minerals such as Fool's Gold, which is a pyrite.[32] These are called "lode" deposits. Native gold is also found in the form of free flakes, grains or larger nuggets that have been eroded from rocks and end up in alluvial deposits (called placer deposits). Such free gold is always richer at the surface of gold-bearing veins owing to the oxidation of accompanying minerals followed by weathering, and washing of the dust into streams and rivers, where it collects and can be welded by water action to form nuggets. Gold sometimes occurs combined with tellurium as the minerals calaverite, krennerite, nagyagite, petzite and sylvanite, and as the rare bismuthide maldonite (Au2Bi) and antimonide aurostibite (AuSb2). Gold also occurs in rare alloys with copper, lead, and mercury: the minerals auricupride (Cu3Au), novodneprite (AuPb3) and weishanite ((Au, Ag)3Hg2). Recent research suggests that microbes can sometimes play an important role in forming gold deposits, transporting and precipitating gold to form grains and nuggets that collect in alluvial deposits.[33] Production Main articles: Gold prospecting, Gold mining, and Gold extraction World gold production trend Gold output in 2005 The entrance to an underground gold mine in Victoria, Australia Pure gold precipitate produced by the aqua regia refining process Gold extraction is most economical in large, easily mined deposits. Ore grades as little as 0.5 g/1000 kg (0.5 parts per million, ppm) can be economical. Typical ore grades in open-pit mines are 1–5 g/1000 kg (1–5 ppm); ore grades in underground or hard rock mines are usually at least 3 g/1000 kg (3 ppm). Because ore grades of 30 g/1000 kg (30 ppm) are usually needed before gold is visible to the naked eye, in most gold mines the gold is invisible. Since the 1880s, South Africa has been the source for a large proportion of the world's gold supply, with about 50% of all gold ever produced having come from South Africa. Production in 1970 accounted for 79% of the world supply, producing about 1,000 tonnes. However by 2007 production was just 272 tonnes. This sharp decline was due to the increasing difficulty of extraction, changing economic factors affecting the industry, and tightened safety auditing. In 2007 China (with 276 tonnes) overtook South Africa as the world's largest gold producer, the first time since 1905 that South Africa has not been the largest.[34] The city of Johannesburg located in South Africa was founded as a result of the Witwatersrand Gold Rush which resulted in the discovery of some of the largest gold deposits the world has ever seen. Gold fields located within the basin in the Free State and Gauteng provinces are extensive in strike and dip requiring some of the world's deepest mines, with the Savuka and TauTona mines being currently the world's deepest gold mine at 3,777 m. The Second Boer War of 1899–1901 between the British Empire and the Afrikaner Boers was at least partly over the rights of miners and possession of the gold wealth in South Africa. Other major producers are the United States, Australia, Russia and Peru. Mines in South Dakota and Nevada supply two-thirds of gold used in the United States. In South America, the controversial project Pascua Lama aims at exploitation of rich fields in the high mountains of Atacama Desert, at the border between Chile and Argentina. Today about one-quarter of the world gold output is estimated to originate from artisanal or small scale mining.[35] After initial production, gold is often subsequently refined industrially by the Wohlwill process or the Miller process. Other methods of assaying and purifying smaller amounts of gold include parting and inquartation as well as cuppelation, or refining methods based on the dissolution of gold in aqua regia. The world's oceans hold a vast amount of gold, but in very low concentrations (perhaps 1–2 parts per 10 billion, e.g. every cubic kilometer of water could contain 10 to 20 kg of gold). But more realistic estimates put the amount of gold on average at 13 parts per trillion;[36] concentrations of 1 ppb seem to have been identified in the discharge of rivers that run though placer deposits. A number of people have claimed to be able to economically recover gold from sea water, but so far they have all been either mistaken or crooks. A so-called reverend, Prescott Jernegan ran a gold-from-seawater swindle in the United States in the 1890s. A British fraudster ran the same scam in England in the early 1900s.[37] Fritz Haber (the German inventor of the Haber process) did research on the extraction of gold from sea water in an effort to help pay Germany's reparations following World War I.[38] Based on the published values of 2 to 64 ppb of gold in seawater a commercially successful extraction seemed possible. After analysis of 4000 water samples yielding an average of 0.004 ppb it became clear that the extraction would not be possible and he stopped the project.[39] No commercially viable mechanism for performing gold extraction from sea water has yet been identified. Gold synthesis is not economically viable and is unlikely to become so in the foreseeable future At the end of 2006, it was estimated that all the gold ever mined totaled 158,000 tonnes[40] and its January 2009 issue, National Geographic magazine writes: "In all of history, only 161,000 tons of gold have been mined, barely enough to fill two Olympic-size swimming pools."[1] This can be represented by a cube with an edge length of about 20.28 meters. The value of this is very limited; at $1000 per ounce, 161,000 tons of gold would have a value of only 5.2 trillion dollars. The average gold mining and extraction costs were about US$317/oz in 2007, but these can vary widely depending on mining type and ore quality; global mine production amounted to 2,471.1 tonnes.[41] Gold is so stable and so valuable that it is always recovered and recycled. There is no true consumption of gold in the economic sense; the stock of gold remains essentially constant while ownership shifts from one party to another.[42] Consumption India is the world's largest consumer of gold, as Indians buy about 25% of the world's gold,[43] purchasing approximately 800 tonnes of gold every year. India is also the largest importer of the yellow metal; in 2008 India imported around 400 tonnes of gold.[44] Chemistry Although gold is a noble metal, it forms many and diverse compounds. The oxidation state of gold in its compounds ranges from -1 to +5, but Au(I) and Au(III) dominate its chemistry. Au(I), referred to as the aurous ion, is the most common oxidation state with soft ligands such as thioethers, thiolates, and tertiary phosphines. Au(I) compounds are typically linear. A good example is Au(CN)2-, which is the soluble form of gold encountered in mining. Curiously, aurous complexes of water are rare. The binary gold halides, such as AuCl, form zig-zag polymeric chains, again featuring linear coordination at Au. Most drugs based on gold are Au(I) derivatives.[45] Au(III) (auric) is a common oxidation state and is illustrated by gold(III) chloride, AuCl3. Au(III) complexes, like other d8 compounds, are typically square planar. Aqua regia (Royal Water), a 1:3 mixture of nitric acid and hydrochloric acid, dissolves it. Nitric acid oxidizes the metal to +3 ions, but only in minute amounts, typically undetectable in the pure acid because of the chemical equilibrium of the reaction. However, the ions are removed from the equilibrium by hydrochloric acid, forming AuCl4– ions, or chloroauric acid, thereby enabling further oxidation. Some free halogens react with gold.[46] Gold also reacts in alkaline solutions of potassium cyanide. With mercury, it forms an amalgam. Less common oxidation states Less common oxidation states of gold include -1, +2, and +5. The -1 oxidation state occurs in compounds containing the Au- anion, called aurides. Caesium auride (CsAu), for example, crystallizes in the caesium chloride motif.[47] Other aurides include those of Rb+, K+, and tetramethylammonium (CH3)4N+.[48] Gold(II) compounds are usually diamagnetic with Au–Au bonds such as [Au(CH2)2P(C6H5)2]2Cl2. The evaporation of a solution of Au(OH)3 in concentrated H2SO4 produces red crystals of gold(II) sulfate, AuSO4. Originally thought to be a mixed-valence compound, it has been shown to contain Au4+2 cations.[49][50] A noteworthy, legitimate gold(II) complex is the tetraxenonogold(II) cation, which contains xenon as a ligand, found in [AuXe4](Sb2F11)2.[51] Gold pentafluoride and its derivative anion, AuF-6, is the sole example of gold(V), the highest verified oxidation state.[52] Some gold compounds exhibit aurophilic bonding, which describes the tendency of gold ions to interact at distances that are too long to be a conventional Au–Au bond but shorter that van der Waals bonding. The interaction is estimated to be comparable in strength to that of a hydrogen bond. Mixed valence compounds Well-defined cluster compounds are numerous.[48] In such cases, gold has a fractional oxidation state. A representative example is the octahedral species {Au(P(C6H5)3)}62+. Gold chalcogenides, such as gold sulfide, feature equal amounts of Au(I) and Au(III). Toxicity Pure metallic (elemental) gold is non-toxic and non-irritating when ingested[53] and is sometimes used as a food decoration in the form of gold leaf. Metallic gold is also a component of the alcoholic drinks Goldschläger, Gold Strike, and Goldwasser. Metallic gold is approved as a food additive in the EU (E175 in the Codex Alimentarius). Although gold ion is toxic, the acceptance of metallic gold as a food additive is due to its relative chemical inertness, and resistance to being corroded or transformed into soluble salts (gold compounds) by any known chemical process which would be encountered in the human body. Soluble compounds (gold salts) such as gold chloride are toxic to the liver and kidneys. Common cyanide salts of gold such as potassium gold cyanide, used in gold electroplating, are toxic both by virtue of their cyanide and gold content. There are rare cases of lethal gold poisoning from potassium gold cyanide.[54][55] Gold toxicity can be ameliorated with chelation therapy with an agent such as Dimercaprol. Gold metal was voted Allergen of the Year in 2001 by the American Contact Dermatitis Society. Gold contact allergies affect mostly women.[56] Despite this, gold is a relatively non-potent contact allergen, in comparison with metals like nickel.[57] Price Main articles: Gold as an investment and Gold standard Gold price per troy ounce in USD since 1960, in nominal US$ and inflation adjusted in 2008 US$. Like other precious metals, gold is measured by troy weight and by grams. When it is alloyed with other metals the term carat or karat is used to indicate the amount of gold present, with 24 carats being pure gold and lower ratings proportionally less. The purity of a gold bar or coin can also be expressed as a decimal figure ranging from 0 to 1, known as the millesimal fineness, such as 0.995 being very pure. The price of gold is determined through trading in the gold and derivatives markets, but a procedure known as the Gold Fixing in London, originating in September 1919, provides a daily benchmark price to the industry. The afternoon fixing was introduced in 1968 to provide a price when US markets are open. Historically gold coinage was widely used as currency; When paper money was introduced, it typically was a receipt redeemable for gold coin or bullion. In an economic system known as the gold standard, a certain weight of gold was given the name of a unit of currency. For a long period, the United States government set the value of the US dollar so that one troy ounce was equal to $20.67 ($664.56/kg), but in 1934 the dollar was devalued to $35.00 per troy ounce ($1125.27/kg). By 1961 it was becoming hard to maintain this price, and a pool of US and European banks agreed to manipulate the market to prevent further currency devaluation against increased gold demand. Swiss-cast 1 kg gold bar On March 17, 1968, economic circumstances caused the collapse of the gold pool, and a two-tiered pricing scheme was established whereby gold was still used to settle international accounts at the old $35.00 per troy ounce ($1.13/g) but the price of gold on the private market was allowed to fluctuate; this two-tiered pricing system was abandoned in 1975 when the price of gold was left to find its free-market level. Central banks still hold historical gold reserves as a store of value although the level has generally been declining. The largest gold depository in the world is that of the U.S. Federal Reserve Bank in New York, which holds about 3%[citation needed] of the gold ever mined, as does the similarly laden U.S. Bullion Depository at Fort Knox. In 2005 the World Gold Council estimated total global gold supply to be 3,859 tonnes and demand to be 3,754 tonnes, giving a surplus of 105 tonnes.[58] Since 1968 the price of gold has ranged widely, from a high of $850/oz ($27,300/kg) on January 21, 1980, to a low of $252.90/oz ($8,131/kg) on June 21, 1999 (London Gold Fixing).[59] The period from 1999 to 2001 marked the "Brown Bottom" after a 20-year bear market.[60] Prices increased rapidly from 1991, but the 1980 high was not exceeded until January 3, 2008 when a new maximum of $865.35 per troy ounce was set (a.m. London Gold Fixing).[61] Another record price was set on March 17, 2008 at $1023.50/oz ($32,900/kg)(am. London Gold Fixing).[61] In the fall of 2009, gold markets experience renewed momentum upwards due to increased demand and a weakening US dollar. On December 2nd 2009, Gold passed the important barrier of US$1200 per ounce to close at $1215.[62] Since April 2001 the gold price has more than tripled in value against the US dollar,[63] prompting speculation that this long secular bear market has ended and a bull market has returned.[64] Symbolism Gold bars at the Emperor Casino in Macau Gold has been highly valued in many societies throughout the ages. In keeping with this it has often had a strongly positive symbolic meaning closely connected to the values held in the highest esteem in the society in question. Gold may symbolize power, strength, wealth, warmth, happiness, love, hope, optimism, intelligence, justice, balance, perfection, summer, harvest and the sun. Great human achievements are frequently rewarded with gold, in the form of gold medals, golden trophies and other decorations. Winners of athletic events and other graded competitions are usually awarded a gold medal (e.g., the Olympic Games). Many awards such as the Nobel Prize are made from gold as well. Other award statues and prizes are depicted in gold or are gold plated (such as the Academy Awards, the Golden Globe Awards, the Emmy Awards, the Palme d'Or, and the British Academy Film Awards). Aristotle in his ethics used gold symbolism when referring to what is now commonly known as the "golden mean". Similarly, gold is associated with perfect or divine principles, such as in the case of Phi, which is sometimes called the "golden ratio". Gold represents great value. Respected people are treated with the most valued rule, the "golden rule". A company may give its most valued customers "gold cards" or make them "gold members". We value moments of peace and therefore we say: "silence is golden". In Greek mythology there was the "golden fleece". Gold is further associated with the wisdom of aging and fruition. The fiftieth wedding anniversary is golden. Our precious latter years are sometimes considered "golden years". The height of a civilization is referred to as a "golden age". In Christianity gold has sometimes been associated with the extremities of utmost evil and the greatest sanctity. In the Book of Exodus, the Golden Calf is a symbol of idolatry. In the Book of Genesis, Abraham was said to be rich in gold and silver, and Moses was instructed to cover the Mercy Seat of the Ark of the Covenant with pure gold. In Christian art the halos of Christ, Mary and the Christian saints are golden. Medieval kings were inaugurated under the signs of sacred oil and a golden crown, the latter symbolizing the eternal shining light of heaven and thus a Christian king's divinely inspired authority. Wedding rings have long been made of gold. It is long-lasting and unaffected by the passage of time and may aid in the ring symbolism of eternal vows before god and/or the sun and moon and the perfection the marriage signifies. In Orthodox Christianity, the wedded couple is adorned with a golden crown during the ceremony, an amalgamation of symbolic rites. In popular culture gold holds many connotations but is most generally connected to terms such as good or great, such as in the phrases: "has a heart of gold", "that's golden!", "golden moment", "then you're golden!" and "golden boy". Gold also still holds its place as a symbol of wealth and through that, in many societies, success.

Today's Total Visit 3085............

আজকের রাশিফল


21 Mar-20 Apr Aries মেষ	21 Apr-21 May Taurus বৃষ	22 May-21 Jun Gemini মিথুন

22 Jun-22 Jul Cancer কর্কট	23 Jul-23 Aug Leo সিংহ	24 Aug-23 Sep Virgo কন্যা

24 Sep-23 Oct Libra তুলা	24 Oct-22 Nov Scorpio বৃশ্চিক	23 Nov-21 Dec Sagittarius ধনু

22 Dec-20 Jan Capricorn মকর	21 Jan-18 Feb Aquarius কুম্ভ	19 Feb-20 Mar Pisces মীন

I have a confession: This whole story idea started as a joke in the office, kind of a "what-if" game. As in, "What if we dared someone to not use... read more>>

So if you haven't heard, Kate Gosselin has abandoned her trademark 'do and is now sporting extensions and side-swept bangs. Personally, I think any ne... read more>>

My feet are firmly encased in boots for the next couple months, but I still can't seem to give up pampering my toes. Even though I'm the only one who... read more>>

We’ve done our part to add to the statement lip discourse currently going on in the beauty world by making an effort to keep you abreast of the shades... read more>>

Full disclosure: I used to be a major mascara snob. I happily applied cheap eyeshadow, blush and lipgloss, but when it came to mascara I turned my nos... read more>>

SELF scored a sneak peek of The Dr. Oz Show this afternoon where he reveals the six most diet-busting dishes ever! See the list, after the jump... <... read more>>

Italian Stallion Pasta Salad is full of heart healthy grains (see more about the importance of grains here) , antioxidant-rich vegetables, and vinegar... read more>>

By WomansDay.com Staff
10 Gluten-Free Desserts

10 Gluten-Free Desserts

Whether you’re avoiding gluten because you have celiac disease... read more>>