Question

Amongst the following, the total number of species not having eight electrons around the central atom in the outermost shell is:

NH₄, AlCl₃, BeCl₂, CCl₄, PCl₅

Options

• 2

• 4

• 1

• 3

Answer 1

3

Explanation:

Total number of species = 3

In AlCl₃ the octet is incomplete with 6e⁻.

BeCl₂ has an octet with 4e⁻.

PCl₅ has a super/hypervalent octet with 10e⁻.

Therefore, since AlCl₃, BeCl₂ and PCl₅ do not follow the octet rule, there are three such species in total. Hence, 3 is the correct answer.