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Physical states of matter
Class 9 · Chemistry · 10 questions
Name: ____________________ Date: ____________
Which state of matter has a fixed shape and a fixed volume?
- A Gas
- B Solid
- C Liquid
- D Plasma
The change of a solid directly into a gas is called:
- A Condensation
- B Sublimation
- C Melting
- D Freezing
At the same temperature, which gas diffuses the fastest?
- A Carbon dioxide
- B Oxygen
- C Hydrogen
- D Chlorine
Boyle's law says that at constant temperature the volume of a gas is inversely proportional to its:
- A Pressure
- B Colour
- C Mass
- D Density only
Evaporation takes place:
- A Only in a vacuum
- B At any temperature, from the surface
- C Only at the boiling point
- D Only in solids
A gas at 2 atm pressure has a volume of 4 L. At constant temperature, what is the volume at 4 atm?
- A 4 L
- B 2 L
- C 8 L
- D 1 L
Gas pressure is caused by:
- A Weight of the gas only
- B Heat only
- C Collisions of gas molecules with the walls
- D Colour
The process of a gas turning into a liquid is:
- A Condensation
- B Sublimation
- C Melting
- D Evaporation
Which state has the lowest density?
- A Gas
- B Liquid
- C Solid
- D All equal
Diffusion is fastest in:
- A Gases
- B All equal
- C Solids
- D Liquids
Answer key
1. B, 2. B, 3. C, 4. A, 5. B, 6. B, 7. C, 8. A, 9. A, 10. A
Particles in a solid are held in fixed positions.
Sublimation is solid to gas without passing through the liquid state.
Lighter molecules move faster. Hydrogen is the lightest.
At constant temperature, P V is constant.
Evaporation happens at the surface of a liquid at any temperature.
P1 V1 = P2 V2, so V2 = 2 x 4 / 4 = 2 L.
Molecules hit the walls and exert force.
Gas to liquid is condensation.
Gas particles are far apart.
Gas molecules move freely and quickly.