Chapter 3. Matter and Its Properties
Matter is anything that has mass and takes up space. It exists in common states: solid, liquid, gas and plasma [6][7].
States of matter
| State | Shape | Volume | Particle motion |
| Solid | Fixed | Fixed | Vibrate in place |
| Liquid | Takes container shape | Fixed | Slide past one another |
| Gas | Takes container shape | Fills container | Move freely, far apart |
Changes of state: melting, freezing, evaporation, condensation, sublimation and deposition. Heating adds energy; at a phase change the energy goes into changing the state, not the temperature.
Properties. Physical properties (density, melting point, colour, solubility) can be observed without changing the substance. Chemical properties (flammability, reactivity) describe how a substance changes into others. Density = mass / volume.
Classification. Pure substances are elements or compounds. Mixtures can be homogeneous (solutions) or heterogeneous. Mixtures are separated by physical methods such as filtration, distillation and chromatography [6].
Review: A block has mass 54 g and volume 20 cm³. What is its density? (Answer: 2.7 g/cm³.)