Which of the following are evidences for the particulate nature of matter?

I. Evaporation

II. Sublimation

III. Diffusion

IV. Brownian motion

Correct answer: I, II, III and IV.

Why:

• Evaporation (I): Only surface particles with enough kinetic energy escape into the gas phase — this shows matter is made of moving particles.
• Sublimation (II): Solids like iodine or dry ice go straight to gas, implying discrete particles that can separate when energy is sufficient.
• Diffusion (III): Gases/liquids mix on their own due to random motion of particles — a direct particulate effect.
• Brownian motion (IV): The zigzag motion of tiny specks in a fluid arises from collisions with invisible, fast-moving particles.

Hence, all four phenomena are evidences for the particulate nature of matter.