A.ldentify the changes as physical or chemical
1. An Ice cube is placed in the sun. Later there is a puddle of water. Later still the puddle is gone.
2.Two chemical are mixed together and a gas is produce. 3. A bicycle changes color as it rusts.
4. Solid is crushed to a powder. 5. Two substances are mixed and light is produced.
6. A piece of ice melts and reacts with sodium
7. Mixing salt and pepper.
8. Chocolate syrup is devolved in milk.
9. Marshmallow is toasted over a campfire.
10. A marshmallow is cut in half.
Answers
Answer:
1) physical change
2)chemical change
3) chemical change
4) chemical change
5) chemical change
6) chemical change
7)physical change
8) physical change
9)chemical change
10) chemical change
Identifying the changes as physical or chemical in the following statements by referring to the
below definition:
Physical changes:
- It is a temporary change.
- In this type of change, only the physical appearance or state of the given substance or compound changes.
- These changes are reversible.
- This type of change does not bring about any change in the chemical composition of the substance.
Chemical changes:
- This is a permanent change.
- In this type of change, the physical as well as the chemical composition of the substance or compound changes.
- This type of change is irreversible.
1. Physical change; it is physical because here the state of ice i.e. solid changes to water i.e. liquid. it is a reversible change too.
2. Chemical change; because the two chemicals mix to form gas with different compositions.
3. Chemical change; because rusting occurs in the presence of oxygen and is irreversible, which is a chemical change.
4. Physical change; because a solid crushed to powder can be reversed, it only changes the appearance of the solid.
5. Chemical change; because here the substance mix to produce light, the composition of the two substances changes, and the change is irreversible.
6. Chemical & physical change; here melting of ice is physical as a change of state occurs whereas reacting with sodium is a chemical change as it is irreversible.
7. Physical change; because mixing salt and pepper doesn't change their composition and it is reversible.
8. Physical change; here, the chemical composition of milk and chocolate syrup does not change after devolving.
9. Chemical change; because burning or cooking is a chemical change, here toasting of marshmallows.
10. Physical change; Cutting marshmallows is a physical activity and it doesn't change the chemical composition of marshmallows.