Chemistry C1

C1a. 1

All substances are made of atoms.
Elements contain only one type of atom.
Different atoms can bond together giving, taking or sharing electrons to form compounds.
Limestone is made mainly of calcium carbonate.
Limestone is widely used in building.
Limestone breaks done when we heat it strongly to make quicklime and carbon dioxide.
Some carbonates decompose when we heat them in a Bunsen flame.
When water is added to quicklime it produces slaked lime.
Lime mortar is made by mixing slaked lime with sand and adding water.
Cement is made by heating limestone with clay in a kiln.
Concrete is made by mixing crushed rocks, cement and sand with water.
Glass is made by heating powdered limestone, sand and sodium carbonate together very strongly.

1 of 3

The Earth's crust contains many different elements.
A metal ore contains enough of the metal to make it economically worth extracting
The reactivity series is useful in deciding the best way to extract a metal from its ore.
Metal more reactive than carbon cannot be extracted from its ore using carbon (you have to use electrolysis).
We extract iron from iron ore by reducing it with carbon in a blast furnace.
The solid, raw materials used to make iron are iron ore, coke and limestone.
Pure iron is too soft for it to be useful.

2 of 3

Carefully controlled quantities of elements are added to iron to make alloys of steel with different properties.
The hardness of steels is related to their carbon content.
Alloys are mixtures of metals, designed to improve their properties.
Smart alloys, also called shape memory alloys, return to their orginal shape on heating (used in medicine and dentistry).
Copper and aluminium are all alloyed with other metals to make them more useful.
Scientists are looking at new ways to extract copper that will use less energy.
Aluminium and titanium are useful because they resist corrosion but they are expensive to extract.

3 of 3