# Charge on flourine?

1. Jul 20, 2014

### Murtuza Tipu

Transition elements can form ions with different charges. Why can't elements other than transition elements form ions with different charges? If it is a Fluoride ion, why does it have to be an anion of charge -1? Why can't it have a -2 charge, or more?

2. Jul 21, 2014

### DrDu

Who said so? Most main group elements can have several oxidation states, e.g. tin forms both $\mathrm{Sn^{2+}}$ and $\mathrm{Sn^{4+}}$ ions. It is true that fluorine and oxygen mostly form ions with charge -1 and -2, respectively, however, even for oxygen, there are other possibilities, like the peroxide ion $\mathrm{O_2^{2-}}$ where each oxygen only bears one negative charge. Elements like sulfur come in a wealth of oxidation states ranging from -2 to +6.