Question

How does the metallic character vary on moving down the group 15? Give suitable explanation for the observed order.

Answer 1

1. Metallic character increases down group 15 from nitrogen (N) to bismuth (Bi).
2. This happens because atomic size increases on moving down the group due to the addition of electron shells.
3. Larger atomic size means valence electrons are held less tightly by the nucleus.
4. Ionisation energy decreases down the group, making it easier to lose electrons.
5. Hence, elements become more electropositive and show higher metallic character.
6. N and P are nonmetals, As and Sb are metalloids, and Bi is a metal because of this trend.

This explanation is based on the increase in atomic size and decrease in ionisation energy leading to increased metallic character down group 15.