which of the following elements exhibits the strongest tendency for catenation?

Options

A. `N`
B. `P`
C. `As`
D. `Sb`

Answer

2

Explanation

`N equiv N` bond is very strong,its very high bond enthalpy of `942" kJmol"^(-1)` is nearly six times the `N-N` bond enthalpy ,`157" kJmol"^(-1)`. On the contary ,`P equiv P` bond is quite weak,its bond dissociation enthalpy of ,`490" kJmol"^(-1)` is only `~2.5` times `P-P` bond enthalpy ,`290" kJmol"^(-1)`. Therefore ,nitrogen exists as a diatomic molecules `N equiv N` ,Whilst phosphorous exists as tetraatomic `P_(4)` molecules in the gasesous state.
In constrast to `N` phosphorus (on account of relatively strong `P-P` bond) shows a distinct tendency for catentation forming both cyclic and open chain compounds several `P` atoms.