A physical change is a change in which no new matters are formed.
Let's get started:
1. a rusting bicycle
This is NOT a physical change because a new substance is formed.
3Fe+ 2O2 -> Fe3O4
2. breaking glass
This is a physical change.
3. melting butter
This is a physical change.
You just change the phase of butter from solid to liquid, but still there is no new substance formed.
4. burning leaves
When you burn something organic, CO2 will be formed.
Therefore, this is NOT a physical change.
5. cutting your hair
This is a physical change.
6. frying an egg
When you fry an egg, iron (Fe) in the yolk reacts with hydrogen sulfide (H2S) in the white to form iron sulfide (FeS).
Therefore, this is NOT a physical change.
7. water evaporating
With the same reason as 3, this is a physical change.
8. mixing salt and water
This is a physical change (with the same reason as 3).
NaCl (s)+ H2O -> NaCl (aq)
Hope this helps~
