Question

Classify the following into element, compound and mixtures:

Coal, methane, carbon dioxide, sugar solution, granite, aluminium, graphite, hydrogen peroxide, blood, soil and sugar.

Answer 1

1. Elements: A pure substance that can neither be reduced further nor can be formed by physical or chemical methods and is made up of same type of atoms.
2. Out of the given examples Aluminium ($\mathrm{Al}$), and Graphite ( an allotrope of carbon) are classified as elements.
3. Compounds: It is a substance that is formed by mixing two or more elements in a defined ratio.
4. Examples of compounds are - Methane is a compound of carbon and hydrogen (${\mathrm{CH}}_4$), carbon dioxide is a compound of carbon and oxygen (${\mathrm{CO}}_2$), and hydrogen peroxide is a compound of hydrogen and oxygen in a fixed ratio (${\mathrm{H}}_2{\mathrm{O}}_2$).
5. Mixtures: It is a substance made by mixing two or more pure substances in an undefined proportion.
6. Examples of mixtures - Coal ( mixture of minerals), granite, sugar solution ( a mixture of sugar and water), blood ( mixture of cells, proteins and plasma), soil and sugar(mixture of two substances).