Intermolecular forces of attraction are least effective in

$(a)$ Explain with the help of an activity which shows that particles of matter are very small.
$(b)$ Define matter. Name the states of matter in which the forces between the constituent particles are
$(i)$ strongest
$(ii)$ weakest
$(c)$ When sugar and common salt are kept in different jars,they take the shape of the jars. Are they solid? Justify your answer.

Name the state of matter in which
$(i)$ layers of particles can slip and slide over one another easily.
$(ii)$ particles just move around randomly because of very weak force of attraction.

Name the state of matter in which:
$(a)$ Layers of particles can slip and slide over one another easily.
$(b)$ Particles just move around randomly because of very weak force of attraction.

Comment on the following statements :
$(a)$ Evaporation produces cooling.
$(b)$ Rate of evaporation of an aqueous solution decreases with increase in humidity.
$(c)$ Sponge though compressible is a solid.

Why is oxygen called a gas? Support your answer by giving two reasons.