Question

Why are the melting and boiling points of polonium lower than those of selenium?

Answer 1

1. The melting and boiling points of polonium are lower than those of selenium due to the inert pair effect.
2. Polonium has a maximum nuclear charge in group 16, which makes its s-electron pair less available for bonding.
3. This reduced availability weakens the intermolecular van der Waals forces in polonium.
4. As a result, polonium’s lower van der Waals forces cause it to have lower melting and boiling points compared to selenium.

Thus, the inert pair effect in polonium leads to weaker intermolecular forces and consequently lower melting and boiling points than selenium.