Boiling is a __________ phenomenon.

Explanation for the correct option(s)

The correct option is (A) bulk

1. Boiling is a bulk phenomenon.

2. The process which involves total molecules including interior molecules along with surface molecules is called a bulk phenomenon.

3. Boiling is considered a bulk phenomenon because total molecules (interior along with surface molecules) are involved during the boiling of any liquid.

4. In boiling, the particles of the bulk of liquid gain energy and then get converted into a gaseous or vapor state.

Explanation for the incorrect option(s)

Option(D): During evaporation, only surface molecules will be involved so it is considered a surface phenomenon.

Option(C): Atmospheric phenomenon is an observable occurrence of particular physical (as opposed to dynamic or synoptic) significance within the atmosphere.