Question

Group 15 elements has higher ionization enthalpy as compared to group 14 elements due to:

• A. Smaller size
• B. Half-filled p-orbital
• C. Larger size
• D. Fully-filled p-orbital

Answer 1

Answer: (A), (B)

Half-filled p-orbital

As we move across the period, atomic size decreases due to which the valence electrons of group 15 are more tightly held to the nucleus as compared to group 14 elements. Hence the ionization enthalpy of group 15 elements is higher than that of group 14 elements.
The extra stable half-filled p-orbital in group 15 elements make it more difficult to remove one electron. Thus increasing the ionization enthalpy.
Hence option (c) is the correct answer.