Summary:
- Three states of matter exist – solid, liquid, and gas.
- Each state has its own unique set of physical properties.
- Mercury is the only metal we know of that is liquid at room temperature.
- Mercury can be solidified when its temperature is brought to its freezing point.
- However, when returned to room temperature conditions, mercury does not exist in solid state for long.
- All substances can exist in any of these three states.
- Technically speaking a fourth state of matter called plasma exists, but it does not naturally occur on earth.