Question

Draw the electron dot structure of

1. Nitrogen molecule (N=7)
2. Sodium chloride [Na =11, Cl= 17]
3. Ammonium ion [N=7, H=1]

Answer 1

Lewis dot structure

G.N Lewis, an American chemist, introduced a simple notation to represent valence electrons in an atom. This notation is called Lewis dot structure

i) Nitrogen molecule (N₂)

Electronic configuration of N is 2,5.

It needs three more electrons to attain noble gas configuration.

So it shares three electrons with other N atom. Hence form triple covalent bond

$:\mathrm{N}⋮+⋮\mathrm{N}:\to :\mathrm{N}\overline{)⋮⋮}\mathrm{N}:$

ii) Sodium chloride

Sodium - 2,8, 1. Its valence electron is 1. It is represented as $\mathrm{Na}·$

Chlorine - 2,8,7. Its valence electron is 7. It is represented as $\underset{··}{\overset{··}{:\mathrm{Cl}·}}$

$Na·+·\underset{··}{\overset{··}{Cl}}:\to {\left[Na\right]}^{+}{\left[··\underset{··}{\overset{··}{Cl}}:\right]}^{-}orNaCl$

iii) Ammonium ion

$\mathrm{H}:\underset{\stackrel{··}{\mathrm{H}}}{\overset{\underset{··}{\mathrm{H}}}{\mathrm{N}}}:+{\mathrm{H}}^{+}\to {\left[\mathrm{H}\underset{\stackrel{··}{\mathrm{H}}}{\overset{\underset{··}{\mathrm{H}}}{:\mathrm{N}:}}\mathrm{H}\right]}^{+}$