Solids, liquids and gases. In a solid like this brick, the particles are regularly arranged touching their neighbours and move only by vibrating. This explains why solids have a fixed shape.

Dissolving a solid in a liquid depends on the interactions and attractions between the molecules of the liquid (solvent) and the particles of the solid (solute). Dissolving happens when the attraction ...

Flows involving solid particles are used extensively in the chemical process industries, including areas such as petrochemicals, pollution control, powder technology, coal combustion, and ...

We tend to understand this using a simplified model in which we imagine matter is made of spherical particles. In this model, solids have particles fixed tightly together in rows so they can’t move.

In quantum physics, subatomic particles behave strangely—they can be in two places simultaneously, move through solid objects ...