Why do gases show high compressibility?

Arrange the three states of matter in the increasing order of:
$(i)$ rate of diffusion
$(ii)$ particle motion

Give the reason for the existence of the three states of matter.

$(i)$ Name the $SI$ unit of measuring temperature.
$(ii)$ The boiling point of water is $100^{\circ} C$ under normal atmospheric pressure. Convert this temperature into $SI$ units.

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.

Give reasons to explain why:
$(i)$ Carbon dioxide is called a gas?
$(ii)$ $A$ gas fills a vessel completely?
$(iii)$ Gases are so easily compressible,whereas it is impossible to compress a solid or a liquid.