Question

part b. instructions: for each of the following changes, identify it as a physical or chemical change. 1) melting ice cream = 2) frying an egg = 3) cracking an egg = 4) cutting hair = 5) balling up paper = 6) burning wood = 7) digesting your lunch = 8) iron rusting = 9) silver tarnishing = 10) filing your fingernails =

Explanation:

1. Melting ice - cream is a physical change as it only changes the state from solid to liquid without altering the chemical composition.
2. Frying an egg is a chemical change because heat causes proteins in the egg to denature and new chemical compounds are formed.
3. Cracking an egg is a physical change as it only changes the physical appearance and does not change the chemical nature of the egg.
4. Cutting hair is a physical change as it only changes the length and shape of the hair without changing its chemical composition.
5. Balling up paper is a physical change as it only changes the shape of the paper and not its chemical makeup.
6. Burning wood is a chemical change as wood reacts with oxygen to produce carbon - dioxide, water vapor and ash, forming new substances.
7. Digesting lunch is a chemical change as food is broken down by enzymes and acids into simpler substances with different chemical compositions.
8. Iron rusting is a chemical change as iron reacts with oxygen and water to form iron oxide (rust), a new substance.
9. Silver tarnishing is a chemical change as silver reacts with sulfur - containing compounds in the air to form silver sulfide, a new substance.
10. Filing your fingernails is a physical change as it only changes the shape and size of the fingernails without changing their chemical composition.

Answer:

1. Physical change
2. Chemical change
3. Physical change
4. Physical change
5. Physical change
6. Chemical change
7. Chemical change
8. Chemical change
9. Chemical change
10. Physical change