3.2 (a) Ions and ionic bonds

3.2 (a) Ions and ionic bonds

Ion: is a charged atom (i.e. number of protons does not equal number of electrons). They form by losing an electron (reduction) increases charge by 1, or by gaining one (oxidation) decreases charge by 1. Remember OIL RIG: oxidation is loss, reduction is gain. A positively charged atom is called a cation, it is usually a metal. A negatively charged atom is called an anion, it is a non-metal(s).

Ionic bond: the bond formed between ions of opposite charge.

Group 1 metals react with halogens. In the reaction the metal gives one electron to the halogen, as shown below (NOTE the way the ions are represented using brackets and + and – signs)

In a reaction a metal gives a non-metal its valency electrons.

An ionic compound (in solid state) has a regular arrangement (lattice) of alternating positive and negative ions.