MATTER
Everything that occupies a space and has mass is called matter. Mass and volume are two common properties of all matters. Our pens, houses, computers, the water we drink are all examples for matter.
States of Matter
In nature substances can be found in three different physical states: solid, liquid and gas.
Solids: Have definite shape and volume. High attraction force between particles. Incompressible
Liquids: Have definite volume but takes the shape of he container. Intermediate attraction force between particles. Incompressible
Gases: Have neither a definite shape nor a volume. Very low attraction force between particles. Compressible
Phase Changes
When the particles of a substance gain or lose energy, the phase (physical state) of the substance may change. Each phase change process has a unique name.
Melting Evaporating
Solid 
Liquid 
Gas
Freezing Condensation
Classification of Matter
Pure Substances
Pure substances are composed of one kind of atoms or molecules. They are classified as elements and compounds.
Elements: are the basic units of matter that can not be decomposed by ordinary chemical methods into simpler substances. Ex: oxygen, hydrogen, iron, gold, carbon, etc…
Compounds: are substances that are composed of two or more elements in fixed proportions. Ex: water, sugar, salt…
Mixtures
Mixtures are made by mixing two or more different pure substances. Mixtures do not have a fixed composition. Mixtures with different combinations have different properties.
Homogeneous mixtures: Have single phase and same properties throughout.
Ex: air, tea, salty water, sugar and water…
Heterogeneous mixtures: Have phases with different properties.
Ex: soup, chalk and water, gasoline and water…
Separation of Mixtures
Mixtures can be separated by using some properties of the components:
- If they are immiscible and have different density, one can separate the components of the mixture by using separator funnel.(water and gasoline)
- If one of the components is magnetic and other is non-magnetic, components can be separated by using a magnet.(iron and wood)
- If one of the components is liquid and other is an insoluble solid, components can be separated by using a filter paper.(sand and water)
- If the components have different temperature of phase change, they can be separated by evaporation or solidification one of the components.(salty water)