# What is the number of dots in the electron dot symbol of nitrogen?

Jul 10, 2016

In dinitrogen gas, ${N}_{2}$, there are 5 valence electrons associated with each nitrogen atom.

#### Explanation:

$N$, $Z = 7$, and thus 7 electrons associated with the neutral atom.

Two of these electrons are inner core, and do not participate in bonding. The remaining 5 electrons are the valence electrons, and 6 of these bind between the nitrogen nuclei together in forming chemical bonds.

Given that a single bond is composed of 2 electrons, the $: N \equiv N :$ representation clearly shows the disposition of the 10 remaining electrons.

If we look at nitrogen compounds, the simplest one is ammonia, $: N {H}_{3}$, which is (i) hard to make; and (ii) absolutely vital to agriculture. Nitrogen here is considered to be neutral because it has 2 electrons from its lone pair, and a half share of the 6 electrons that make up the $3 \times N - H$ bonds. $5 + 2 \text{ inner shell electrons}$ balance the charge of the 7 protons in the nitrogen nucleus.

But nitrogen is a base, and has a formal lone pair, which is conceived to form a donative bond to ${H}^{+}$ in an acid base reaction:

$N {H}_{3} \left(a q\right) + {H}_{2} O r i g h t \le f t h a r p \infty n s N {H}_{4}^{+} + H {O}^{-}$

The nitrogen centre is now quaternized, and is depicted with a formal positive charge (6 electrons rather than the 7 required for neutrality).