A polyatomic ion.
Examples: Sulfate, Sulfite, Nitrate, Nitrite...
The formation of chemical bonds occurs due to the attractive forces between oppositely charged ions (ionic bonds) or by sharing of electrons (covalent bonds).
An atom having tendency of attracting a shared pair of electrons towards itself and this chemical property is said to Electronegativity .
Thus, the attractive forces which draws in surrounding electrons for chemical bonds is electronegativity.
22) Oxygen with a -2 charge
23) Neon with a +2 charge
24) Fluorine with a -1 charge
25) Lithium with a +1 charge