Question

Classify the following into elements, compounds and mixtures. (a) Sodium (b) Soil (c) Sugar solution (d) Silver (e) Calcium carbonate (f) Tin (g) Silicon (h) Coal (i) Air (j) Soap (k) Methane (l) Carbon dioxide (m) Blood.

Answer 1

Elements:

1. An element is a pure substance that has only one type of atom in it.
2. Most of them are metals.

Compound:

1. A compound is a pure substance made up of more than one type of element which is chemically bonded together in fixed ratios and can be represented by a chemical formula.
2. For example carbon dioxide is made up of two different elements i.e. two oxygen atoms and one carbon atom and has a chemical formula ${\mathrm{CO}}_2$, so it is a compound.

Mixture:

1. A mixture is an impure substance made up of different elements or compounds mixed together that are not chemically bonded.
2. Mixtures can be separated by using techniques like filtering and distillation.
3. For example air is a mixture that contains the elements nitrogen, oxygen, the compound carbon dioxide, and many more.

So, we can classify the given substances as-

Elements	Compounds	Mixture
Sodium, silver, tin, silicon	Calcium carbonate, carbon dioxide, methane	Soil, sugar solution, coal, air, blood, soap