Physical + Chemical Changes

Question 1

Physical Change

Answer 1

When a substance changes size, state or other features BUT DOESN’T become a new substance. It doesn’t affect the identity of a substance and are reversible

Question 2

Chemical Change

Answer 2

The original substance is changed into one or more new substances with different physical/chemical properties. These changes affect the identity of the substance and can be detected by signs that a reaction has occured.

Question 3

Evidence of Chemical Change

Answer 3

1. Colour change from within
2. Production of gas or odour
3. Release or absorption of heat
4. Production of light or sound
5. Total loss of identity
6. Formation of a precipitate (solid comes out of solution)
7. Temperature change
8. Very difficult/impossible to reverse

Question 4

Exothermic

Answer 4

Chemical reaction in which energy is primarily given off in the form of heat.

Question 5

Endothermic

Answer 5

Chemical reaction occurring or formed with absorption of heat.