Physical Change

Physical changes in a substance affect its physical properties

No new substance is formed during a physical change.

Physical changes are usually reversible.

Ice into water…

Melting ice into water…

Is this an example of physical change?

Ask yourself:‘Can water be turned back into ice?’

(i.e can the change be reversed?)

Dissolving salt into water

Is this an example of Physical change?

Can you write down a method for reversing this process?

Chemical Change

Changes of matter that produce new substances.

The new substances have chemical properties which are different from the original substances.

Chemical changes are usually difficult to reverse.

Signs of chemical change

There is a permanent colour change A gas is given off There is a change in temperature A precipitate (solid) forms when two

liquids are mixed Light is emitted

Can you think of others?