《IGCSE science Chemistry study notes》C10- Metals

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Metals have giant structures of atoms with strong metallic bonding.

o Therefore, most metals have high melting and boiling points.

o They can conduct heat and electricity because of the delocalised

electrons in their structures.

o The layers of atoms in metals are able to slide over each other, so metals

can be bent and shaped. (malleable)

An alloy is . The other elements may be metals, nonmetals, or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden.

Alloys are, for example, generally harder than pure metals. . This means that the layers of atoms cannot slide over each other easily, making the whole alloy much stronger than any of the pure metals that the alloy contains in isolation.

A mixture of two or more metals is called an alloy. An alloy is not just a mixture of the metal crystals, the atoms of the second metal are part of the crystal lattice.

most reactive

Potassium – people

Sodium - still

Calcium - can't

Magnesium - meet

Carbon - common

Zinc - zebras

Iron - in

Lead - large

Copper – countries

least reactive

. Carbon has displaced the metal from the oxide. The carbon monoxide is oxidised further to produce the less harmful carbon dioxide, CO 2. Copper may be extracted from copper oxide by reaction with carbon.

The bauxite is purified to produce aluminium oxide, a white powder from which aluminium can be extracted. The extraction is done by electrolysis. The ions in the aluminium oxide must be free to move so that electricity can pass through it.

Ore- The naturally occurring material from which a mineral or minerals of economic value can be extracted.

ore bauxite- Bauxite is the . Extraction of aluminium metal takes place in three main stages: mining of bauxite ore, refining the ore to recover alumina, and smelting alumina to produce aluminium. Other raw materials are mined as aluminium ore, but their use is minor compared with bauxite.

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Electrolysis- process by which electric current is passed through a substance to effect a chemical change.

Metal ore deposits are a finite resource and non-renewable.

Many metals are obtained today from recycling (melting and refining) scrap metals.About half of the aluminium, copper, lead, steel and tin that is used in the UK come from recycled scrap metal.

An ore is a rock from which metals can be extracted. The main ore of iron is hematite, which contains large amounts of iron(III) oxide. It is reduced by carbon to for iron, but this takes place in a huge blast furnace.

The raw materials needed to do this are hematite, coke, limestone and air.

The hematite, coke and limestone are added at the top of the furnace. A strong current of hot air is blown in at the bottom of the furnace. It is hot enough to react with the coke.

At the bottom of the furnace, the coke burns in the hot air blast to form carbon dioxide. This is an exothermic reaction and the heat released keeps the furnace hot.

-C + O2 -> CO2

The carbon dioxide produced reacts with the coke to form carbon monoxide:

-CO2 + C -> 2CO

This carbon monoxide reduces the iron(III) oxide to iron:

-Fe2O3 + 3CO -> 2Fe + 3CO2

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