Physical & Chemical Changes

Question 1

Describe a physical change

Answer 1

1. Doesn’t change the identity of the matter
2. Easy to observe
3. Doesn’t form a new substance
4. Bending, melting, freezing, dissolving, cutting, etc

Question 2

Describe a chemical change

Answer 2

1. Changes into new matter that has different properties
2. Change in reactivity
3. Hard to observe
4. Difficult to reverse
5. Creates new substances
6. Burning, rusing

Question 3

What do physical and chemical changes have in common?

Answer 3

1. Both have some sort of change
2. Can be observed
3. Uses matter

Question 4

What are four common clues that show that a chemical change has occurred?

Answer 4

1. Temperature change (TriangleT or Delta T)
2. Gas is produced
3. Precipitate (solids form)
4. Color change

Question 5

If you see one of the four common clues that a chemical change has occurred, does this mean that it is a chemical change?

Answer 5

No, this does not always mean that it is a chemical change