Question

physical and chemical changes
identify if the actions depict a physical or chemical change.

1. cutting an apple physical change chemical change
2. baking a cookie physical change chemical change
3. burning wood physical change chemical change
4. melting ice physical change chemical change
5. rotting fruit physical change chemical change
6. digesting food physical change chemical change
7. boiling water physical change chemical change
8. chopping wood physical change chemical change
9. frying an egg physical change chemical change
10. rusting nail physical change chemical change

Explanation:

Step1: Recall physical - chemical change rules

Physical change: no new substances formed, mainly change in shape or state. Chemical change: new substances formed.

Step2: Analyze cutting an apple

Only changes shape, no new substances. So it's a physical change.

Step3: Analyze baking a cookie

Ingredients react to form new substances. So it's a chemical change.

Step4: Analyze burning wood

Wood reacts with oxygen to form new substances like carbon - dioxide. So it's a chemical change.

Step5: Analyze melting ice

Only changes from solid to liquid, no new substances. So it's a physical change.

Step6: Analyze rotting fruit

Chemical reactions occur, new substances are formed. So it's a chemical change.

Step7: Analyze digesting food

Food is broken down chemically to form new substances. So it's a chemical change.

Step8: Analyze boiling water

Only changes from liquid to gas, no new substances. So it's a physical change.

Step9: Analyze chopping wood

Only changes shape, no new substances. So it's a physical change.

Step10: Analyze frying an egg

Proteins in egg denature and new substances are formed. So it's a chemical change.

Step11: Analyze rusting nail

Iron reacts with oxygen and water to form rust (new substance). So it's a chemical change.

Answer:

1. physical change
2. chemical change
3. chemical change
4. physical change
5. chemical change
6. chemical change
7. physical change
8. physical change
9. chemical change
10. chemical change