NEET Chemistry: Structure of Solids questions with solutions

Q1. Metallic lustre exhibited by sodium is due to:

1. diffusion of sodium ion
2. oscillation of loose electron
3. escalation of free protons
4. existence of lattice structure

Answer: oscillation of loose electron

Sodium shows metallic lustre because its loosely held valence electrons are free to oscillate when light falls on the surface. These oscillating electrons reflect much of the incident light, producing the shiny appearance.