Sorting Materials into Groups

Metals have luster (shine). Give reason why some metal articles become dull and lose their shine.

Why is a tumbler not made with a piece of cloth?

What are the similarities between iron, copper and aluminium?

What is the reason for grouping materials?

Grouping of objects helps the shopkeeper.' Justify the statement.

Why is water important for our body?

Suggest two bases on which we can group objects.

Write any four properties of materials.