Question

(1) The melting and boiling points of Zn, Cd, and Hg are low.

Hint:

- Fully filled d-orbitals weaken metallic bonding. - Strong metallic bonding requires unpaired d-electrons.

Answer 1

The melting and boiling points of Zn, Cd, and Hg are low due to the absence of unpaired electrons in their d-orbitals, leading to weak metallic bonding between atoms.
Electronic Configuration and Bonding - Zn, Cd, and Hg belong to Group 12 and have a completely filled d\(^ {10}\) configuration. - The lack of unpaired d-electrons reduces the extent of metallic bonding, making these metals soft with low melting and boiling points.
Weak Interatomic Forces - In transition metals, strong metallic bonding arises due to overlapping of d-orbitals. - However, in Zn, Cd, and Hg, fully filled d-orbitals do not contribute to bonding, resulting in weak interatomic forces and low melting/boiling points.