Page 71 - ICSE Chemistry 6

3. Which of the following have closely packed par cles?
(a) Solids (b) Liquids (c) Gases (d) All of these
4. Which of the following diff use quickly?
(a) Solids (b) Liquids (c) Gases (d) All of these
5. Which of the following can be compressed to some extent?
(a) Solids (b) Liquids (c) Gases (d) All of these
6. What is the process of conversion of a liquid into a solid called?
(a) Freezing (b) Condensa on (c) Sublima on (d) Evapora on
D. Match the columns.
Column A Column B
1. Conversion of a solid into a liquid (a) Vaporiza on

2. Conversion of a gas into a liquid (b) Chemical change
3. Conversion of a solid into a gas (c) Mel ng
4. Conversion of a liquid into a vapour (d) Sublima on
5. Burning of a candle (e) Condensa on

SHORT AND PRECISE

A. Show the given text in the form of fl owcharts.
1. States of ma er, their proper es and examples 2. Change in states of ma er

B. Give reasons for the following statements.
1. The three states of ma er are diff erent from each other.
2. Solids are fi rm, compact and almost incompressible.
3. Ice kept at room temperature for 5–10 minutes changes into water.
4. Water kept in a freezer of a refrigerator changes into ice.
5. Gas changes into liquid state on cooling.
6. Gases can be compressed easily.
7. Water changes into water vapour on hea ng.
8. Naphthalene balls are placed in cupboards between woollen clothes to keep insects away.

C. Answer in short.
1. Defi ne ma er. Give examples.
2. What are solids? How are molecules arranged in solids?
3. How are molecules arranged in gases?
4. Explain why solids are hard and diffi cult to compress.
5. Defi ne freezing and freezing point.
6. What is vaporiza on? Name its two types.
7. What is condensa on? Defi ne condensa on point.
8. What happens on hea ng a solid?

AT LENGTH

A. Diff eren ate between the following.
1. Mass and weight 2. Solids, liquids and gases

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