<P> Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales (iron rusts over years, while potassium burns in seconds). Examples: </P> <Dl> <Dd> 4 Na + O → 2 Na O (sodium oxide) </Dd> <Dd> 2 Ca + O → 2 CaO (calcium oxide) </Dd> <Dd> 4 Al + 3 O → 2 Al O (aluminium oxide). </Dd> </Dl> <Dd> 4 Na + O → 2 Na O (sodium oxide) </Dd> <Dd> 2 Ca + O → 2 CaO (calcium oxide) </Dd>

Where are metals usually found on the periodic table