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Charlotte Anne Moss and Sasha Marie Brookes.

gold, aluminium and their alloys . Charlotte Anne Moss and Sasha Marie Brookes. GOLD. Gold, Au, has long been prized for its beauty, resistance to chemical attack, and workability. It occurs as a native metal. It has a relatively low melting point (1063 oC. ),

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Charlotte Anne Moss and Sasha Marie Brookes.

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  1. gold, aluminium and their alloys Charlotte Anne Moss and Sasha Marie Brookes.

  2. GOLD • Gold, Au, has long been prized for its beauty, resistance to chemical attack, and workability. • It occurs as a native metal. • It has a relatively low melting point (1063 oC.), • It is malleable, and easily separated from rock • It is usually cast or hammered into beautiful designs.

  3. AND THE FACTS CARRY ON.. • Gold crystallizes in the cubic system, forming octahedral and dodecahedral crystals. • Gold can be made harder by alloying it with copper, silver, and other metals. • Most gold contains some silver. Pure gold is very dense, with a specific gravity of 19.3, decreasing to 15.6 as silver connate increases. • Gold is the most malleable and ductile substance known. • Gold is also one of the most resistant metals. It won't tarnish, discolour, crumble, or be affected by most solvents.

  4. HOW IS GOLD FORMED? • The mineral Gold is almost always mixed with a small amount of silver, and sometimes contains traces of copper and iron. • Most Gold is mined from ore, containing tiny amounts of Gold in the ore. The ore is brown, iron-stained rock or massive white Quartz. • To extract the gold, the ore is crushed, then the gold is separated from the ore by various methods. Gold is less commonly found as nuggets. Nuggets are formed when erosion causes a large piece of Gold to separate from its mother rock, and then gets carried away into a stream or river. The flowing water tumbles the Gold, giving each specimen a distinct shape. The Gold eventually settles at the bottom of the water, and due to its heaviness remains there

  5. ALIMINUM Pure aluminium is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking. It is somewhat decorative. It is easily formed, machined, and cast. Pure aluminium is soft and lacks strength, but alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties. Aluminium is an abundant element in the earth's crust, but it is not found free in nature. The Bayer process is used to refine aluminium from bauxite, an aluminium ore. Table: basic information about and classifications of aluminium. • Symbol: Al • Atomic number: 13 • Atomic weight: 26.9815386 (8) • Standard state: solid at 298 K • CAS Registry ID: 7429-90-5 • Group in periodic table: 13 • Group name: (none) • Period in periodic table: 3 • Block in periodic table: p-block • Colour: silvery • Classification: Metallic

  6. Aluminium alloys • Aluminium alloys are mixtures of aluminium with other metals (called an alloy), often with copper, zinc, manganese, silicon, or magnesium. They are much lighter and more corrosion resistant than plain carbon, steel, but not as corrosion resistant as pure aluminium. Bare aluminium alloy surfaces will keep their apparent shine in a dry environment due to the formation of a clear, protective oxide layer.

  7. GOLD ALLOYS • For most uses of gold the pure metal is too soft on its own and is therefore hardened by the addition of alloying elements, copper, silver, nickel, palladium and zinc. Gold is of course yellow and the various colours seen such as red, white and green are simply alloys of gold. The final colour is dependent on the ratios and type of alloys added.

  8. THE END THANKYOU FOR READING LOVEYOU XXXXXXXXXXXXXXXXXXXXXXXXX

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