Physical Change
What is a physical change?
A change in the State, Size or Shape without changing the substance.
What is a chemical change?
A change that results in a new substance.
What does irreversible mean?
A change that cannot be undone.
What does reversible mean?
A change that can be undone.
Give an example of a physical change.
Melting ice into water.
Give an example of a chemical change.
Burning wood.
Can you give an example of an irreversible change?
Cooking an egg.
Give an example of a reversible change.
Freezing and melting water.
What happens to the state of water when it freezes?
It changes from liquid to solid (ice).
What are some signs that a chemical change has occurred?
Changes in color, temperature, or formation of gas.
Why is burning paper an irreversible change?
Because it creates ash and smoke.
What is a common reversible change that happens when you inflate a balloon?
The balloon can return to its original shape when deflated.
Can you name a physical change that can be reversed?
Boiling water can turn into steam, and then the steam can condense back into water.
Can you name a chemical change that is irreversible?
Baking a cake.
What happens to the substances in an irreversible change?
They undergo chemical reactions that produce new substances.
Why is dissolving sugar in water considered a reversible change?
Because the sugar can be recovered by evaporating the water.
What is the difference between a physical change and a chemical change?
A physical change does not change the substance, while a chemical change does.
Why is rusting considered a chemical change?
Because it forms a new substance (rust) from iron and oxygen.
What are some common irreversible changes that happen in nature?
Erosion.
Can you describe a reversible change in terms of temperature?
Melting or Freezing.