Elements Are classified to 3 groups: 1.Metals 2.Non-Metals 3.Metalloids
Examples of Elements : Oxygen, Carbon
A compounds is formed when 2 or more different elements combine together by a chemical reaction.Compound can be split to smaller substances.But elements is made up of 1 or more atoms of the same types.Element is a pure substances, it cannot be split up to something smaller.And A mixture is formed when 2 more substances are mixed together by a physical method such as stirring, shaking, dissolving.
Chemical change - A change that is very hard to reverse.May reverse the change by heat or electricity.Example : Burning fossil fuel Physical change - Can be easily reversed.Does not change the properties of the substances.Example : Scrambled paper
Examples of Compounds - When magnesium (Mg) burns with oxygen (O), there is a lot of heat and light.This is a chemical reaction, we get a compound: Magnesium oxide (MgO) Examples of Mixtures - Mixtures of gases in the air.No chemical reaction.No new substance is formed.All elements keep their properties.
Types of Mixtures - Homogeneous and Heterogeneous Homogeneous : Solution (Less than 1nm) Heterogeneous : Colloid (1nm - 1000nm), Suspension (More than 1000nm)
