Chemistry C1a: Rocks and Building (AQA)

What you are expected to know:

• All substances are made of atoms that have a tiny central nucleus surrounded by electrons.
• The simplest substances contain only one type of atom and are called 'elements'
• Atoms of each element have their own chemical symbol
• The periodic table lists all the known elements in groups with similar chemical properties
• Elements form compounds by combining with other elements: their atoms give, take or share electrons, so they bond together.
• The formula of a substance shows the types of atom it contains and how many have combined together.
• In chemical reactions, the mass of the reactants is always the same as the mass of the products
• Chemical equations are balanced. There is the same number of each type of atom on each side.
• Limestone is used as a building material and to make quicklime, slaked lime, cement and glass.
• Heating metal carbonates produces metal oxides and carbon dioxide gas.

Atoms, elements and compounds

• There are about 100 different elements from which all substances are made
• Elements are listed in the periodic table
• Each element is made of one type of atom.
• Atoms are represented by a chemical symbol, e.g. Na for sodium, O for oxygen.
• Atoms have a tiny nucleus surrounded by electrons. When elements react their atoms join with atoms of other elements
• Atoms form chemical bonds by losing, gaining or sharing a small number…