Page 25 - ICSE Chemistry 8

EXERCISES

BE PROMPT

A. Fill in the blanks.
1. Ma er exists in three states: ___________, ______________ and ___________.

2. The par cles of ma er are separated by __________________.
3. The ____________________ are negligible in gases.

4. The total mass during a chemical reac on remains ______________.

B. Iden fy the error in the given statements. Circle the incorrect word and write the correct word in
the blank.
1. Liquids have fi xed shape and volume. __________________
2. The par cles of ma er possess poten al energy. __________________

3. The par cles of ma er in solids are far from each other. __________________
4. Magnesium chloride is formed on burning magnesium in air. __________________

C. Match the columns.
Column A Column B

1. Distance between par cles of ma er (a) Intermolecular force of a rac on
2. Forces of a rac on between par cles (b) Mass – neither created nor destroyed
of ma er
3. Mass in a chemical reac on (c) Intermolecular space

4. Law of conserva on of mass (d) Remains constant

SHORT AND PRECISE

A. Show the given text in the form of fl owcharts.
1. Three states of ma er
2. Kine c theory in context to three states of ma er

B. Give reasons for the following statements.
1. The molecules are closely packed in solids.

2. The molecules are less closely packed in liquids as compared to solids.
3. The molecules are far away from each other in gases.
4. The mass in a chemical reac on remains constant.
5. Liquids evaporate on hea ng.

C. Answer in short.
1. What is ma er? What are the three states of ma er?
2. What does the kine c molecular theory of ma er state?

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