← Back to the activity

Class 8 Science — The particulate nature of matter

Explain the three states of matter by how tightly their particles are held and how much space sits between them.

Name: ________________________

  1. 1.Liquids and gases share two properties that solids do not: they flow, and they do not hold a fixed shape. What are the two of them called together?

    • a) Solutions
    • b) Fluids
    • c) Vapours
    • d) Mixtures

  2. 2.What is the difference between boiling and evaporation, as the chapter puts it?

    • a) Boiling turns a liquid into a solid; evaporation turns it into a gas
    • b) Boiling happens at one temperature and throughout the liquid; evaporation happens at any temperature and at the surface
    • c) Boiling happens at the surface; evaporation happens throughout the liquid
    • d) Boiling is slow and evaporation is fast

  3. 3.A solid is heated until it melts. Put the four stages back into order.

    • The particles vibrate more vigorously
    • The solid turns into a liquid
    • The vibrations grow strong enough that particles leave their positions
    • The interparticle forces of attraction weaken

  4. 4.A grain of potassium permanganate is dropped into hot water, water at room temperature and ice-cold water. Where does the colour spread fastest, and why?

    • a) At the same rate in each of the three, because the grain is the same size
    • b) In the ice-cold water, because cold water holds more colour
    • c) In the room-temperature water, because the particles are most settled there
    • d) In the hot water, because heating makes the particles move faster

  5. 5.What are the spaces between the particles of a substance called? Give the two words.

  6. 6.Match each solid from the chapter's table to its melting point, in degrees Celsius.

    • Ice
    • Urea
    • Iron
    • 1538
    • 133
    • 0

  7. 7.Now sort the same three by how much room sits between their particles.

    Groups: Least space between particles · A little more space than in a solid · Most space between particles

    • Liquid
    • Solid
    • Gas

  8. 8.An incense stick is lit in one corner of a room and the fragrance is soon noticed across it. What does that show?

    • a) Air particles stand still while the fragrance particles push past them
    • b) The fragrance particles are pulled towards people
    • c) The particles of air are moving constantly and carry the fragrance particles with them
    • d) Smoke is heavier than air and rolls along the floor

Answer key — Class 8 Science — The particulate nature of matter

  1. 1. b) Fluids
  2. 2. b) Boiling happens at one temperature and throughout the liquid; evaporation happens at any temperature and at the surface
  3. 3. 1. The particles vibrate more vigorously 2. The vibrations grow strong enough that particles leave their positions 3. The interparticle forces of attraction weaken 4. The solid turns into a liquid
  4. 4. d) In the hot water, because heating makes the particles move faster
  5. 5.
    • interparticle spaces
    • interparticle space
  6. 6. Ice → 0; Urea → 133; Iron → 1538
  7. 7. Solid → Least space between particles; Liquid → A little more space than in a solid; Gas → Most space between particles
  8. 8. c) The particles of air are moving constantly and carry the fragrance particles with them