Last updated on August 30th, 2023 at 01:45 am
At what point do the particles of a liquid have enough energy to break free from the forces of attraction and change into a gas?
- a) Freezing point
- b) Melting point
- c) Boiling point
- d) Condensation point
Answer: c) Boiling point
What is the temperature at which a liquid starts boiling at atmospheric pressure called?
- a) Melting point
- b) Freezing point
- c) Boiling point
- d) Condensation point
Answer: c) Boiling point
What are substances called that change directly from a solid state to a gaseous state without going through the liquid state?
- a) Volatile substances
- b) Non-volatile substances
- c) Sublimation substances
- d) Fusion substances
Answer: c) Sublimation substances
At a given temperature, what is the state of motion of particles in any gas, liquid, or solid?
- a) They are at rest
- b) They move in a straight line
- c) They vibrate in fixed positions
- d) They are always moving
Answer: d) They are always moving
What is the process called when a liquid changes into vapor at any temperature below its boiling point?
- a) Condensation
- b) Sublimation
- c) Evaporation
- d) Fusion
Answer: c) Evaporation
Does evaporation occur only at the boiling point of a liquid?
- a) Yes, evaporation can only occur at the boiling point.
- b) No, evaporation can occur at any temperature.
- c) Evaporation occurs only in gases, not in liquids.
- d) Evaporation is not a natural process.
Answer: b) No, evaporation can occur at any temperature.
Which factor has the greatest influence on the rate of evaporation?
- a) Surface area
- b) Temperature
- c) Humidity
- d) Wind speed
Answer: b) Temperature
What happens when acetone (nail polish remover) is poured on the palm?
- a) The particles gain energy from the palm and evaporate, causing the palm to feel cool.
- b) The palm absorbs energy from the acetone, causing the palm to feel warm.
- c) The acetone absorbs energy from the surroundings, causing the palm to feel cool.
- d) The particles gain energy from the surroundings and condense on the palm, causing the palm to feel cool.
Answer: a) The particles gain energy from the palm and evaporate, causing the palm to feel cool.
Why do people sprinkle water on the roof or open ground after a hot sunny day?
- a) To conserve water
- b) To attract birds
- c) To increase humidity in the surroundings
- d) To take advantage of the cooling effect of evaporation due to the high latent heat of vaporization of water
Answer: d) To take advantage of the cooling effect of evaporation due to the high latent heat of vaporization of water
Why should we wear cotton clothes in summer?
- a) Cotton clothes are fashionable and trendy.
- b) Cotton clothes help in conserving water.
- c) Cotton clothes absorb sweat and facilitate evaporation, keeping the body cool.
- d) Cotton clothes prevent evaporation and retain heat.
Answer: c) Cotton clothes absorb sweat and facilitate evaporation, keeping the body cool.
Which state of matter has the maximum forces of attraction between particles?
- a) Solid
- b) Liquid
- c) Gas
- d) Plasma
Answer: a) Solid
In which state of matter are the spaces between particles and kinetic energy maximum?
- a) Solid
- b) Liquid
- c) Gas
- d) Plasma
Answer: c) Gas
What is the process called when a solid changes directly into a gas without going through the liquid state?
- a) Melting
- b) Boiling
- c) Sublimation
- d) Evaporation
Answer: c) Sublimation
What is the process called when a gas changes directly into a solid without going through the liquid state?
- a) Melting
- b) Boiling
- c) Sublimation
- d) Deposition
Answer: d) Deposition
What is the heat energy required to change 1 kg of a liquid to gas at atmospheric pressure at its boiling point called?
- a) Latent heat of fusion
- b) Latent heat of vaporization
- c) Specific heat capacity
- d) Heat of combustion
Answer: b) Latent heat of vaporization
What is the heat energy required to change 1 kg of solid into liquid at its melting point called?
- a) Latent heat of fusion
- b) Latent heat of vaporization
- c) Specific heat capacity
- d) Heat of combustion
Answer: a) Latent heat of fusion
