Science
Class 9
Matter in Our Surroundings - Worksheet for Class 9 Chemistry
States, changes and the particle picture of matter
This worksheet covers the physical nature of matter, the three states, and how temperature and pressure drive changes of state, with questions to test both recall and reasoning.
True / False
True or False: Particles and States
Read each statement carefully. Write True or False in the blank.
1. Matter is made up of very small particles.
2. Particles in a solid have the maximum space between them.
3. Liquids can be compressed easily, just like gases.
4. Increasing pressure on a gas decreases the space between its particles.
5. The temperature at which a solid melts into a liquid is called its melting point.
6. Evaporation causes cooling because particles lose energy as they escape.
7. Sublimation is the change of a gas directly into a solid without becoming a liquid, or vice versa.
8. Rigidity is a property of gases, not solids.
Fill in the Blanks
Fill in the Blanks
Choose the correct word from the word bank to complete each sentence.
1.The spontaneous mixing of two gases due to the movement of their particles is called .
2.The amount of heat energy required to change 1 kg of a solid into liquid at atmospheric pressure at its melting point is called the .
3.Naphthalene balls disappearing over time without melting is an example of .
4.The temperature at which a liquid starts changing into vapour at atmospheric pressure is its .
5.Particles of matter possess , which increases as temperature rises.
6.Mass per unit volume of a substance is known as its .
Quiz (MCQ)
Multiple Choice Questions
Circle the correct answer for each question.
1. Which factor, when increased, generally increases the rate of evaporation?
2. What happens to the boiling point of water when pressure is increased above sea level normal pressure?
3. Which of these has the strongest force of attraction between its particles?
4. CO2 stored under high pressure as a liquid, when released, quickly changes into which state?
5. Why does a desert cooler work better on a hot dry day than on a humid day?
6. Which change of state releases heat energy rather than absorbing it?
Short Answer
Short Answer Questions
Answer the following in your own words, in 2 to 4 sentences each.
1. Explain why a gas exerts pressure on the walls of its container, using the idea of particle movement.
2. Why does a wet handkerchief dry faster on a hot windy day than on a cold still day? Mention at least two factors.
3. A student says solids cannot flow because their particles are fixed in position. Is this fully correct? Explain what actually allows particle motion even in a solid.
4. Using particle spacing and force of attraction, explain why liquids take the shape of their container but gases fill it completely.
These are open-ended - there's no single right answer to check.
Label the Diagram
Label the Beaker Setup
Look at the numbered picture below. Write the correct term for each labeled part using the word bank.
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Written by Lernizy Editorial Team
Updated 27 Aug 2026