Question

Non-metals are usually poor conductors of heat and electricity. They are non-lustrous, non-sonorous, non-malleable and coloured. Name a lustrous non-metal.

Answer 1

Lustrous:-

1. It basically describes the way in which the light is getting reflected by the surface.
2. Generally, substances having a shiny appearance in nature are lustrous.
3. Metals are basically lustrous and non-metals are not.
4. But there are some exceptions too which exist in the case of non-metals, like iodine.
5. On moving down the group, there is an increase in the size of atoms and so more shells are added therefore because of the screening effect the effective nuclear charge is less and so electrons are also loosely bound.

Therefore, iodine is the only non-metal which is lustrous in nature.