Forming Bonds

When different elements combine they form compounds.

When a metal reacts with a non metal, ions are formed. Metal atoms lose one or more electrons to form positively charged ions. Non-metal atoms gain electrons to form negatively charged ions. The oppositely charged ions attract each other strongly and the compound has ionic bonds.

The chemical formula of an ionic compound tells us the simplest ration of ions in the compound. For example, NaCl shows that sodium chloride is made from equal numbers of sodium ions and chloride ions.

When non-metals combine, their atoms share electrons to form covalent bonds and molecules are formed.

The chemical formula of a molecule tells us the number of atoms that have bonded together in the molecule. For example H20 shows that a water molecule contains two hydrogen atoms and one oxygen atom. Covalent bonds can be shown as lines between the atoms that are bonded together.

	Created by alex_davidson98 almost 12 years ago

GCSE Chemistry Note on C1, created by alex_davidson98 on 14/12/2013.