Matter in Our Surroundings: 100 important questions

Class 9 Science, Chapter 1. Every question below is written the way an exam asks it — practise aloud, then copy the ones you miss.

100 questions Class 9 · Science CBSE pattern

100 questions

1. Matter and Its Properties

What is matter? Give two examples.
What are the three states of matter?
Why is air considered a matter?
What is diffusion? Give an example.
Why do gases diffuse faster than liquids?
Why does a gas exert pressure?
What is compressibility? Which state of matter is highly compressible?
Why do solids have a definite shape and volume?
Why can liquids flow but solids cannot?
Why do gases not have a fixed volume?

2. Characteristics of Particles of Matter

What are the characteristics of particles of matter?
Why do particles of matter have space between them?
How does the rate of diffusion depend on temperature?
Why does a gas take the shape of its container?
What happens when sugar is added to water? Which property of matter does it show?
What happens to the particles of matter when heated?
Why does a wooden chair not take the shape of the container in which it is kept?
What is Brownian motion? Give an example.
How does an increase in temperature affect diffusion?
How do we know that particles of matter are constantly moving?

3. States of Matter and Their Interconversion

What is interconversion of states of matter?
Define sublimation with an example.
What is latent heat? Explain its types.
Define the boiling point of a liquid.
Define the melting point of a solid.
Why does the temperature remain constant during the melting of ice?
How does pressure affect the state of matter?
Explain why camphor disappears without leaving any residue.
How can we liquefy gases?
What is condensation? Give an example.

4. Effect of Temperature on States of Matter

How does heat affect the movement of particles?
Why does ice melt at 0°C?
Why does water boil at 100°C?
Why do clothes dry faster in summer than in winter?
Why do we feel cool when we put some acetone or petrol on our palm?
What is the role of latent heat in changing the state of matter?
Why does water remain cool in an earthen pot?
Why do we sweat more on humid days?
Why is ice at 0°C more effective in cooling than water at 0°C?
Why is steam at 100°C more dangerous than boiling water at 100°C?

5. Evaporation

Define evaporation.
What are the factors affecting evaporation?
Why does evaporation cause cooling?
Why do wet clothes dry faster on a windy day?
Why do we feel cool after taking a bath?
Why does the rate of evaporation increase with an increase in temperature?
How does the surface area affect the rate of evaporation?
Why do we feel cold when we apply deodorant or perfume?
Why does a desert cooler work better on a hot, dry day?
Why do farmers sprinkle water on crops during frost?

6. Differences Between States of Matter

Differentiate between solid, liquid, and gas based on shape and volume.
Differentiate between boiling and evaporation.
Differentiate between diffusion in gases and liquids.
Why do gases exert more pressure than solids and liquids?
Why do liquids have a fixed volume but no fixed shape?
Why is boiling considered a bulk phenomenon while evaporation is a surface phenomenon?
Why does the boiling point of water increase when salt is added to it?
What is the difference between melting and freezing?
How is pressure related to the liquefaction of gases?
What is the major difference between gas and vapor?

7. Practical Applications and Daily Life Examples

Why do naphthalene balls disappear over time?
Why does a steel container expand when heated?
How do gases help in inflating a balloon?
Why does ice float on water?
Why do gas cylinders have a warning sign about high pressure?
Why does warm air rise up?
Why do air bubbles expand as they rise in water?
Why do liquid droplets form spherical shapes?
Why does a pressure cooker reduce cooking time?
Why do mountaineers carry oxygen cylinders?

8. Numerical and Graph-Based Questions

A substance melts at 150°C. Is it solid or liquid at room temperature?
Draw a graph showing the change of state of ice to water and then to steam.
A gas is compressed from 10 L to 5 L. How does its pressure change?
If 1 kg of ice absorbs 334 kJ of heat energy, what is its latent heat of fusion?
A liquid at 80°C is left in a room at 30°C. What happens to its temperature over time?

9. Higher-Order Thinking Skills (HOTS) Questions

Why does ice at 0°C feel colder than water at 0°C?
Why is water used in car radiators?
Why does a balloon burst when too much air is blown into it?
Why is LPG stored in liquid form in cylinders?
How does an increase in humidity affect the rate of evaporation?

10. Miscellaneous Conceptual Questions

What is meant by kinetic energy of particles?
How does atmospheric pressure affect boiling point?
What is plasma? How is it different from gas?
What are Bose-Einstein Condensates?
Why do solids have high density compared to liquids and gases?
What is the effect of altitude on boiling point?
Why do gases not have a fixed shape?
Why does dry ice change into gas directly?
Why does alcohol evaporate faster than water?
Why is fog seen more in winter than in summer?
Why do pressure cookers cook food faster?
Why do icebergs float even though they are massive?
Why does salt help in melting ice?
How does a hot air balloon rise?
Why does sweating help cool the body?
Why do some liquids mix while others do not?
Why do helium balloons rise in the air?
Why does warm water dissolve substances faster than cold water?
Why do airplanes leave white trails in the sky?
How does the water cycle demonstrate changes in states of matter?

How to use these 100 questions

Do not try to answer all hundred in one sitting. Split them into five sets of twenty and work through one set a day. For each question, say the answer aloud before you look at your notes — spoken recall exposes gaps faster than re-reading does.

Set 1 (Q1–20): matter, particles and diffusion — the definitions that open every paper.
Set 2 (Q21–40): states of matter and interconversion, with the temperature graph.
Set 3 (Q41–60): evaporation, cooling and the everyday examples examiners love.
Set 4 (Q61–80): comparisons and practical applications.
Set 5 (Q81–100): numericals and HOTS questions — attempt these closed-book.

Mark every question you got wrong. Two days later, redo only those.

Finished the set?

Open the full Class 9 chapter notes, then keep the streak going with the next subject.

Class 9 notes All resources