Assertion : Elemental nitrogen exist as a diatomic molecule and phospours as tetratomic molecule.
Reason :Nitrogen does not have vacant d-orbital wheras phosphorus have vacant d-orbital.

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If assertion is false but reason is true.

Answer

b

Explanation

Elemental nitrogen exiast as a diatomic molecule because nitrogen can form pm-pn multiple bonds which is not possible in case of phosphorus due to repulsion between non- bonded electron of the inter core .There is no such repulsion in case of smaller nitrogen atom as they have only `1s^(2)` electron in their inner core