Question

Which of the following has highest ionization enthalpy?

• A. $P$
• B. $N$
• C. $As$
• D. $Sb$

Answer 1

Answer: (B)

$N$

Answer 2

The electronic configuration of atoms of group 15 are half filled, ie, $(np_{x}^{1},\,\,np_{y}^{1},\,\,np_{z}^{1})$ and are stable therefore, they have high ionization enthalpy. Ongoing down the group, the ionization enthalpy decreases due to increase in atomic size. Hence, $N$ has highest ionization enthalpy.