Question

physical change

1. a change in size, shape, or state
2. no new substance is formed

chemical change

1. a change in the physical and chemical properties
2. a new substance is formed

identify the following as physical (p) or chemical (c) changes.

1. nacl (table salt) dissolves in water.
2. ag (silver) tarnishes.
3. an apple is cut.
4. heat changes h₂o to steam.
5. baking soda reacts to vinegar.
6. fe (iron) rusts.
7. alcohol evaporates.
8. ice melts.
9. milk sours.
10. sugar dissolves in water.
11. wood rots.
12. pancakes cook.
13. grass grows.
14. a tire is inflated.
15. food is digested.
16. paper towel absorbs water.

physical and chemical changes

Explanation:

To solve this, we use the definitions of physical and chemical changes:

• Physical Change (P): Change in size, shape, or state; no new substance formed.
• Chemical Change (C): New substance formed; change in physical/chemical properties.

1. NaCl (Table Salt) dissolves in water.

Step: Check if new substance forms. Dissolving salt is a state change (solid to aqueous), no new substance.

Answer:

P

2. Ag (Silver) tarnishes.

Step: Tarnishing forms silver sulfide (new substance).