# What is the oxidation state of nitrogen in nitrate ion and what is its structure? [duplicate]

What's the oxidation state of nitrogen in $$\ce{NO3-}$$ ion. Simple calculation depicts that it's $$+5$$. But second period elements never show variable oxidation states. And it's structure is so confusing to me. Some people show dative/co-ordinate bonds, whereas others show a positive charge on nitrogen. Which should be considered as correct one?

## marked as duplicate by Martin - マーチン♦, M.A.R. ಠ_ಠ, Klaus-Dieter Warzecha, Freddy, DavePhDJan 30 '15 at 12:53

The $\ce{NO3-}$ ion cannot be depicted using a single Lewis structure. However, its resonance structures are shown below:
• in nitrate the nitrogen uses its p orbitals to bond with the oxygens. however, in a hypthetical $\ce{NCl5}$ molecule the orbital overlap between the chlorine and nitrogen orbitals would be poor due to energy mismatching and steric hindrance between the chlorines and so this molecule is not stable – bon Jan 29 '15 at 21:50