Changes

Q.

What are the biotic and abiotic factors in a forest ecosystem?

Q.

Which features adapt polar bears to live in an extremely cold climate?

1. A white fur, fat below skin, keen sense of smell.

2. Thin skin, large eyes, a white fur.

3. A long tail, strong claws, white large paws

4. White body, paws for swimming, gills for respiration.

Q.

Watermelon is _______ creeper/climber.

Q. Define air

Q. The mirror in your bathroom turns foggy after you take a hot shower. This is due to _____.

1. precipitation
2. condensation
3. evaporation
4. melting

Q.

Copper is diatomic.

1. True
2. False

Q.

Question 16

A potter working on his wheel shaped a lump of clay into a pot. He then baked the pot in an oven. Do these two acts lead to the same kind of changes or different? Give your opinion and justify your answer.

Q.

Why nitrogen gas is used in packaging of food?

Q.

What are reversible and irreversible changes?

Q. Idli batter is steamed to get Idli? Is it a reversible or an Irreversible change justify your answer.

Q. In living organisms, nitrogen is a constituent of

1. amino acids
2. sugars
3. nucleic acids
4. chlorophyll

Q.

Give two medical and industrial uses of oxygen.

Q. Shreya drops a flower vase and the glass scatters all over the floor. Identify the type of change depicted in the given scenario.

1. Irreversible and chemical
2. Irreversible and physical
3. Reversible and chemical
4. Reversible and physical

Q.

Money plant is an example of creeper. Do you agree? Explain?

Q.

What happens when a glowing splinter is introduced in a jar containing oxygen?

Q.

16. You have seen that construction workers heat a black material called coal tar, for repairing a road. State whether the change which has occurred in coal tar on being heated is reversible or irreversible.

Q.

Give one example in each case:

Change occurs on cooling but can be reversed.

Q.

The largest component of air is _____________followed by _________.

Q. The following image shows rusting of iron. What type of change is this?

1. reversible
2. irreversible
3. slow and reversible
4. slow and irreversible

Q.

Name the device used for generating electricity utilising wind energy.

Q.

2. What happens to metals on heating:

1. They expand

2. They contract

3. They remain unaffected

4. None of these

Q.

Souring of milk is a (an) ___________ (desirable/undesirable) change.

Q. is cutting of paper reversible or irreversible

Q.

What is the atomicity of the following?

a) Oxygen

b) Ozone

c) Neon

d) Sulphur

e) Phosphorous

f) Sodium

Q.

Name the most active constituent of the air.

Q.

Pea plant is a creeper.

1. True
2. False

Q. What are the examples of desirable changes.

Q.

A type of change in which we cannot get back the original substance.

Q.

Explain briefly, Tap water contains dissolved salts and gases.

Q.

How is milk converted into curd? Can the milk be obtained again from the curd? What kind of change is this? [3 MARKS]