Water has more mass than kerosene even though though they both have same volume, water has more weight than kerosene.
- Any thing that has weight and occupies space is called matter.
- Matter has mass and occupies space. Matter exists in three states: solid, liquid and gaseous states.
- Matter is made up of tiny particles called a molecule. A molecule can be broken down further into smaller units called atoms.
- In solids, the attraction between molecules is very strong. Solids have fixed shape, size and volume.
- In a liquid, the attraction between molecules is not very strong, but molecules stay together. Liquids do not have a fixed shape and can flow freely.
- In a gas, the attraction between molecules is very weak. So, in a gas, molecules move freely. They do not have a fixed shape or size.
- One form of matter can be changed to another form by increasing or reducing the heat. Solids melt to form liquids. Liquids change into gases.
- When a solute is dissolved in a solvent, a solution is formed.
- The amount of space occupied by an object is called its volume.
- The matter that makes up a body is called its mass.
- Water is one of the few known substances which expands when it freezes. Thus, ice occupies more space than water.
- The increase in the size of the matter on heating is called expansion
- The decrease in the size of the matter on cooling is called contraction