An ion is an atom that has lost/gained electrons. For example, in acids, H+ is present, whilst in alkalis OH- is present. Atoms usually do this for ionic bonding, where the outer shells of the atoms are made to have complete (and have a therefore stable) arrangement of electrons.
Simon Cowell, what a dick.
Lucky you doing physics exam.. I had to do bloody ideas in context today and do Physics later this month.
I stopped by i0n's mom's house last night.
Not to fit a mold,
Not to join a trend,
Not to follow a crowd