Matter — Nature and Behaviour

Grade 9 Science — Matter — Nature and Behaviour: 25 practice questions with instant scoring and explanations.

1. Which statement best describes the kinetic theory of matter?
2. A gas has no definite shape or volume. This is because:
3. The process by which a liquid changes into a gas below its boiling point is called:
4. Dry ice (solid CO₂) directly converts to CO₂ gas without becoming liquid. This process is known as:
5. At what temperature do the kinetic energies of particles in solid and liquid states become equal?
6. Which of the following has the highest kinetic energy of particles at the same temperature?
7. A substance has a fixed shape and fixed volume. It must be a:
8. Diffusion is fastest in which state of matter?
9. The SI unit of density is:
10. A solid melts when heated because:
11. Which process involves the conversion of a gas to a liquid?
12. At constant temperature, as pressure on a gas increases, what happens to its volume?
13. A beaker of water is left open on a table. After several days, the water level decreases. This is because of:
14. Which statement is TRUE about the particles in a liquid?
15. The boiling point of a liquid is the temperature at which:
16. A platinum wire glows red when heated to 700°C. This demonstrates:
17. Pressure in a gas is caused by:
18. A 50g piece of ice at 0°C is heated. After melting, the mass of water produced will be:
19. Which state of matter has particles arranged in a definite pattern?
20. When water freezes to ice, the density:
21. A real gas behaves most like an ideal gas when:
22. The compressibility of gas is much greater than that of liquids because:
23. Which process releases energy to the surroundings?
24. The critical point of a substance is the condition at which:
25. In a closed container, evaporation and condensation reach equilibrium when: