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Year 7 Science — Methods of separation

Name the everyday methods for pulling a mixture apart, and pick the right one for a given mixture.

Name: ________________________

Before you start

The stages of clearing a pan of tea, and where the leaves end up at each one.

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  1. 1. Sedimentation — the leaves settle at the bottom
  2. 2. Decantation — the tea is poured off the settled leaves
  3. 3. Filtration — the strainer catches the leaves still floating

Three stages, and each one leaves the tea a little cleaner. Decantation on its own still lets a few leaves through, which is why the strainer comes last.

  1. 1.In churning, where does the butter end up?

    • a) Settled at the bottom, because it is heavier
    • b) Dissolved into the buttermilk
    • c) Floating at the top, because it is lighter
    • d) Spread evenly through the whole mixture

  2. 2.Pieces are picked out of a mixture by hand because they differ in size, colour or shape. What is that method called?

  3. 3.Sort each method by what it pulls apart.

    Groups: A solid from another solid · A solid from a liquid

    • Sieving
    • Evaporation
    • Winnowing
    • Sedimentation
    • Handpicking
    • Magnetic separation
    • Filtration

  4. 4.Iron filings are mixed into a heap of sand. Which method gets the filings out?

    • a) Decantation
    • b) Magnetic separation
    • c) Evaporation
    • d) Winnowing

  5. 5.Salt has been dissolved in water. Which method gets the salt back?

    • a) Handpicking
    • b) Winnowing
    • c) Evaporation
    • d) Filtration

  6. 6.Sand has been stirred into water but has not dissolved. Which method separates it out?

    • a) Evaporation
    • b) Churning
    • c) Threshing
    • d) Filtration

  7. 7.Match each method of separation to what is done in it.

    • Winnowing
    • Sieving
    • Decantation
    • Magnetic separation
    • Threshing
    • passing a mixture through a sieve to separate by particle size
    • using a magnet to draw the magnetic pieces out
    • beating stalks to free the grains
    • blowing air to carry the lighter husk away
    • tilting the vessel to pour the liquid off the settled solid

  8. 8.A farmer drops a mixture of grain and husk from a height on a windy day. Which method is being used?

    • a) Sieving
    • b) Filtration
    • c) Winnowing
    • d) Sedimentation

Answer key — Year 7 Science — Methods of separation

  1. 1. c) Floating at the top, because it is lighter
  2. 2.
    • handpicking
    • hand picking
  3. 3. Handpicking → A solid from another solid; Winnowing → A solid from another solid; Sieving → A solid from another solid; Magnetic separation → A solid from another solid; Filtration → A solid from a liquid; Sedimentation → A solid from a liquid; Evaporation → A solid from a liquid
  4. 4. b) Magnetic separation
  5. 5. c) Evaporation
  6. 6. d) Filtration
  7. 7. Winnowing → blowing air to carry the lighter husk away; Sieving → passing a mixture through a sieve to separate by particle size; Decantation → tilting the vessel to pour the liquid off the settled solid; Magnetic separation → using a magnet to draw the magnetic pieces out; Threshing → beating stalks to free the grains
  8. 8. c) Winnowing