Properties and States of Matter
Matter is anything that has mass and occupies space. The amount of matter that is contained in an object is called mass. The weight of an object is a measure of the gravitational force exerted on it.
There are three states of matter, which are as follows:
- Solids: it has a definite shape and volume. The molecules in it do not move freely. In some solids, such as minerals, the molecules do change in form and orderly pattern called a crystal.
- Liquids: a liquid does not have a specific shape; this is as a result of its molecules which move freely. Liquids only take the shape of a container. But it has a definite shape e.g. water; it is the only substance that is present in all three states of matter.
- Gases: the attraction between the molecules of gas is weak, which makes them move up and down the container they are in. it has no definite volume and shape.
The temperature changes in matter
- Melting point: it is the temperature at which solid changes to liquid.
- Boiling point: it is the temperature at which liquid changes to gas.
- Condensation point: it is the temperature at which gas changes to liquid.
- Freezing point: it is the temperature changes at which liquid becomes solid.
Terms in mixture
Mixtures have to do with physical changes of two or more element, which still retains their physical composition. E.g. Salt-water.
Solutions: are mixtures that are uniform in all aspect and consists of ions, atoms, or molecules of two or more substances.
Solute: is a substance that dissolves in a solution.
Solvent: it is known as the substance in which the solute is dissolved.
- From the options which one of the following physical changes, requires adding heat to a substance? A. Freezing and condensing B. Melting and boiling C. Evaporation and condensing D. Condensing and boiling
2. The molecules of a solid do not move………….?
3. The ……….. Between the molecules of gas is very…………?
4. The temperature at which a solid becomes liquid is known as…………..?
A. Melting point
B. Boiling point
C. Freezing point
D. Condensation point
5. The substance in a solution that is dissolved is known as ………….?