Two students made the lewis dot diagrams of nh3. the diagrams are as shown.
which student drew the correct lewis dot diagram?
only student a
only student b
both student a and student b
neither student a nor student b

Answer :  The correct option is, Only Student B

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The given molecule is,

As we know that nitrogen has '5' valence electrons and hydrogen has '1' valence electron.

Therefore, the total number of valence electrons in = 5 + 3(1) = 8

According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.

The Lewis dot structure of student A is wrong because there is a coordinate bond present between the nitrogen and hydrogen is not covalent.

The correct Lewis-dot structure of is shown by the student B.