The most stable Lewis structure for ( \textSO_4^2- ) is a resonance hybrid of forms with two S=O and two S–O⁻ bonds. One representative Lewis structure is:
.. .. :O: :O: \\ // S // \\ :O: :O: .. .. so4 2 lewis structure
The two S=O and two S–O⁻ bonds are equivalent through resonance — the actual ion has with bond order ~1.5. The most stable Lewis structure for ( \textSO_4^2-