Temporary or Permanent Changes

Q.

Fallen leaves from tree are useful because they

1. Solve the problem of fuel wood in village household

2. Enrich water quality

3. enrich soil fertility

4. Beautify landscape

Q.

Complete the following food chain:

Grass $\to$ Insects $\to$ Frog $\to$ ____$\to$ Eagle

1. Snake

2. Caterpillar

3. Cow

4. Lion

Q. Match the items of Column I with the items of Column II.​

Column - I	Column - II
a. Large crystals​	i. Turns lime water milky​
b. Depositing a layer of zinc on iron​	ii. Physical change​
c. Souring of milk​	iii. Rust​
d. Carbon dioxide​	iv. Carbon dioxide​
e. Iron oxide​	v. Chemical change​
f. Dissolving common salt in water​	vi. Galvanisation​

1. a - iv, b - vi, c - v, d - i, e - iii, f - ii
2. i

Q. Bursting of a balloon and burning of paper are _______ and _______ changes respectively.​

1. chemical, physical ​
2. chemical, periodic​
3. physical, chemical
4. physical, periodic

Q. The decaying leaves and animal droppings in a forest enrich the _______.

1. water
2. soil
3. air
4. fauna

Q. Converting egg to omelette is a reversible change.

1. True
2. False

Q.

Q. Freezing of water to ice is a _______ change.

1. chemical
2. periodic
3. permanent
4. physical

Q. Converting egg to omelette is a reversible change.

1. True
2. False

Q. Freezing of water to ice is a _______ change.

1. permanent
2. physical
3. chemical
4. periodic

Q. Harry went to a bakery and found out that the bread is made from wheat. What type of changes is involved in making of bread?

1. Permanent
2. Temporary
3. Natural
4. Periodic

Q. Classify rising of hot air over a radiator as a physical or a chemical change. Give reasons.

Q. Freezing of water to ice is a _______ change.

1. periodic
2. chemical
3. physical
4. permanent

Q. Give one example in each case. [3 marks]
(a) Change which occurs on heating but can be reversed.
(b) Change which occurs on heating but cannot be reversed.
(c) Change which occurs on cooling but can be reversed.

Q. Burning of a candle is a/an change.

1. reversible
2. irreversible
3. natural