Matter is all around us everything that exists in the universe is made up of matter - from the tiny insects, to the most distant stars in the sky. Most matter is made up of minute particles called atoms. The states forms in which matter usually exists are solid, liquid, or gas.
The solid form of matter has a fixed shape and volume. The solid particles are tightly packed in regular patterns. These particles can vibrate even though they are held very firmly in place through strong forces.
The liquid form of matter has a definite volume but no fixed shape. It can flow and take the shape of its container. The liquid particles are more loosely bound than solid particles. The particles tend to move over short distances.
The gaseous form of matter has no fixed volume or shape and will expand to fill its container. The gas particles are widely spaced and the bonds between the particles are very weak and these particles move freely.
Mass : Mass is the amount of matter in an object.
Volume : Volume is the space the object occupies.
Density : Density is its mass divided by its volume. It is used to compare the heaviness of different materials
Plasma : Plasma is the fourth state of matter. Plasma forms when electrons are torn from their atoms by electricity or heat.
The Changing state : The state of a substance is determined by its temperature. When heated, solids change to liquids, and liquids change to gases because their particles vibrate faster thereby weakening the bonds that hold the particles together. When cooled, gases change (condense) to liquids and liquids to solids. The vibration of their particles slows down and the bonds between them strengthen.
The three states of water is a good example to understand the changing state.
When the temperature of water falls below 0° C (32° F), water takes the form of ice. If the temperature of water rises above 100° C (212° F), water turns into steam. But between these temperatures i.e. 0° C (32° F) and 100° C (212° F), water is in its usual liquid state.
The Kinetic Theory : The kinetic theory of matter states that, particles of matter are constantly in motion. The energy of the “kinetic” (moving) particles determines the temperature and behaviour of matter.
Describing Matter : A material can be described by its physical properties as well as its chemical make-up. The attributes such as colour, shape, texture, smell, hardness, solubility, viscosity and the way the material behaves when forces act on it.