Matter is anything that has mass and takes up space. Matter exists in three states: solid, liquid and gas.
A solid keeps its shape; a liquid flows and takes the shape of its container; a gas spreads to fill all the space. Matter can change state: melting (solid → liquid), freezing (liquid → solid) and evaporation (liquid → gas).
Remember
- Three states: solid, liquid, gas.
- Melt: solid→liquid · Freeze: liquid→solid · Evaporate: liquid→gas.