In what type of matter are atoms most tightly packed?

Solids, liquids, gases and plasmas are four different states of matter. The types of differences that the atoms (particles) can have at a microscopic level are ones mostly examined and explained. The differences in their properties at a macroscopic level is not apparent or can be ignored. Macro refers to the very large.

Solid is the state of matter with the most tightly packed particles/atoms vibrating about a fixed point; they have definite shape and definite volume.

With liquids, they are in a state of matter where packed particles/atoms are able to slide past one another; have definite volume, but no definite shape. Gases work in a state of matter with large amounts of empty space between the particles; they have no definite shape and no definite volume. Lastly, plasma is in a state of matter where a gas has gained enough energy to become ionized; it has no definite shape and no definite volume.