Skip to content
MeerkatSkool Afrikaans
Summaries · Grade 7 Natural Sciences › Choosing a separation method
Free summary · Grade 7 Natural Sciences

Choosing a separation method

How to choose the right separation method, and separate mixtures in steps. Read one part at a time and tap “I know this”. Then test yourself in the quiz.

Know it already? Jump straight to the quiz

Your progress0 of 3

The right method

MixtureMethod
Paper clips and riceMagnet
Pebbles and fine sandSieve
Chalk and waterFilter
Sugar crystals from sugar waterEvaporate
Pure water from salt waterDistil
Colours in a black markerChromatography
Oil and waterLet it settle, then pour off the oil

Chromatography works because each dye travels at its own speed. Seawater is a mixture; a pure substance has only one kind of particle.

How do you separate a mixture?
How do you separate a mixture?
Tap when you could tell someone without looking.

Three steps

Magnet: ironoutAdd water +filter: sandstaysEvaporate:salt remains
Each step uses a different property.
Tap when you could tell someone without looking.

In real life

  • Gold is panned from sand: as you swirl, the heavy gold sinks.
  • Recycling uses separation: magnets pull out steel cans.
  • Water treatment plants remove sand and dirt by settling and sand filters.
  • Never taste substances in the lab to identify them: they may be poisonous or dirty.
Tap when you could tell someone without looking.

Remember this and test yourself

Remember this: your summary
  • Choose the method by the property that differs: size, magnetism, solubility, boiling point.
  • Miscible: two liquids mix completely. Immiscible: oil and water.
  • Decanting: gently pour off the top liquid.
  • In distillation the vapour cools into a liquid in the condenser.
  • Iron, salt and sand: magnet → add water and filter → evaporate.

Write these points in your book. Read them again the night before the test.

Memory trick

Iron, salt, sand: Magnet, Water-and-filter, Evaporate: “My Wet Elephant.”

Flash cards · Tap to turn over

Important words

First say what the word means, then turn the card over.

Test yourself · Part 2

True or false?

Read the question and the answer. Is the answer right? Tap True or False.

    Now the real quiz!

    The quiz has many more questions on this topic. Every question shows straight away whether you are right and explains why.

    Take the quiz: Choosing a separation method
    All Grade 7 Natural Sciences summaries
    For parents
    • Read one part together and ask your child to tell it back in their own words.
    • The ticks (“I know this”) are saved on this device only. We never ask for names or emails.

    Follows CAPS for Grade 7 Natural Sciences. Always check your teacher’s notes and textbook too.

    Free PDF