Question

Which of the following statement is incorrect for group 15 elements ?

• A. The boiling point and melting point increases from top to bottom in the group
• B. Dinitrogen is a gas while all others are solids
• C. Order of ionization enthalpies is ${\Delta }_i{H}_1<{\Delta }_i{H}_2<{\Delta }_i{H}_3$
• D. All of the above

Answer 1

The correct option is A The boiling point and melting point increases from top to bottom in the group

The order of successive ​ionisation enthalpies​ ${\Delta }_i{H}_1<{\Delta }_i{H}_2<{\Delta }_i{H}_3$

The melting point increases from nitrogen to arsenic because of the continuous increment in nuclear size. The low melting point of nitrogen is because of its discrete diatomic particles.
Melting point order: $N<P<As>Sb>Bi$

Dinitrogen is a gas while all others are solids