Online Test — Matter in Our Surroundings
18 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 18
Anything that has mass and occupies space is called:
energy
matter
force
pressure
Explanation: Matter is defined as anything having mass and volume.
Question 2 of 18
Which property is shown when sugar dissolves in water without overflow?
Particles attract each other
Particles have spaces between them
Particles are large
Particles do not move
Explanation: The sugar fits into the spaces between water particles, so the level does not rise.
Question 3 of 18
Diffusion is slowest in:
gases
liquids
solids
vapours
Explanation: In solids particles are fixed, so diffusion is negligible (slowest).
Question 4 of 18
A substance with no fixed shape and no fixed volume is a:
solid
liquid
gas
crystal
Explanation: Gases take both the shape and volume of their container.
Question 5 of 18
Highly compressible state of matter is:
solid
liquid
gas
none
Explanation: Large spaces between gas particles make gases highly compressible.
Question 6 of 18
The fourth state of matter, found in the Sun, is:
plasma
liquid crystal
BEC
vapour
Explanation: Plasma is made of ionised, super-energetic particles, as in the Sun and stars.
Question 7 of 18
The change of a liquid into a solid is called:
melting
freezing
boiling
sublimation
Explanation: Freezing is the liquid-to-solid change at the freezing point.
Question 8 of 18
The boiling point of water in Kelvin is about:
273 K
300 K
373 K
400 K
Explanation: 100 degC + 273 = 373 K.
Question 9 of 18
27°C in Kelvin is:
246 K
300 K
327 K
273 K
Explanation: K = degC + 273 = 27 + 273 = 300 K.
Question 10 of 18
Which substance sublimes on heating?
ice
iron
ammonium chloride
common salt
Explanation: Ammonium chloride changes directly from solid to vapour (sublimation).
Question 11 of 18
The heat absorbed during melting without a rise in temperature is the latent heat of:
vaporisation
fusion
condensation
sublimation
Explanation: Latent heat of fusion is absorbed when a solid melts to a liquid.
Question 12 of 18
Steam at 100°C burns more severely than water at 100°C because steam has extra:
mass
pressure
latent heat of vaporisation
density
Explanation: Steam releases its latent heat of vaporisation on condensing on the skin.
Question 13 of 18
Water boils below 100°C on a mountain because the atmospheric pressure is:
higher
lower
unchanged
zero
Explanation: Lower pressure at altitude lowers the boiling point.
Question 14 of 18
Evaporation takes place:
throughout the liquid
only at the surface
only at boiling point
only in solids
Explanation: Only fast surface particles escape, so evaporation is a surface phenomenon.
Question 15 of 18
Which factor DECREASES the rate of evaporation?
higher temperature
higher wind speed
higher humidity
larger surface area
Explanation: High humidity means the air is near saturation, slowing evaporation.
Question 16 of 18
Water stays cool in an earthen pot because of:
condensation
evaporation through pores
freezing
sublimation
Explanation: Water seeps through the pores and evaporates, taking heat from the water inside.
Question 17 of 18
Evaporation causes cooling because the liquid:
gains heat
absorbs latent heat from surroundings
expands
freezes
Explanation: The liquid absorbs latent heat from its surroundings to keep evaporating, cooling them.
Question 18 of 18
Tea cools faster in a saucer than a cup because the saucer offers a larger:
volume
temperature
surface area
humidity
Explanation: A larger exposed surface area lets more particles evaporate, cooling the tea faster.