What is a Solid?
Solids are one of the four common states of matter - the others are liquids, gases, and plasmas. In general, but not in all specific cases, as the temperature increases and pressure decreases substances pass through the four different states.
solid → liquid → gas → plasma
The Solid State
The solid state of matter is characterized by the following properties:
- its volume is fixed; it will not expand to fill a container - unlike gases and plasmas
- most solids are incompressible - their volume hardly changes when pressure changes - unlike gases and plasmas
- solids are not fluids, so they cannot flow. Their shapes do not adapt to that of their containers - unlike liquids, gases, and plasmas
- solids are condensed matter, so their volumes are similar to those of liquids, and much smaller than gases and plasmas
