When we heat a metal rod, the size of the metal rod changes. It becomes _______.

When we cool a metal wire, the size of the metal wire changes. It becomes ______.

It is when a material can easily return to their original size and shape after going through physical change.

• permanent change

• temporary change

Metal power lines hang down loosely to prevent the wires from ______ when metal becomes cold.

Metal railway tracks have gaps in between them to prevent the tracks from _____ out of shape when the metal becomes too hot.

Ceramic bricks have gaps in between them so that the bricks will not be ______ when the ceramic bricks gets too hot.

• become bigger

• become smaller

• bending out of shape

• pushed out of place

It is the amount of substance in a object.

Mass is measured in _____ and _____.

• litres

• kilograms

• grams

• milliliter

Which of the following materials is/are suitable in making an aquarium?

• wood

• fabric

• plastic

• glass

To measure mass, we use _______ and ______.

• lever balance

• ruler

• thermometer

• fixed masses