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5th grade · Science · Unit 1 of 15

Solutions & Mixtures

Dissolving and separating mixtures

What your child practices

Solutions versus mechanical mixtures, solutes and solvents, what affects dissolving, and ways to separate mixtures (filtering, evaporation, magnets, chromatography).

Texas Essential Knowledge and Skills (TEKS) teks student expectation: 5.6(B); 5.6(C) · mixtures that keep their properties, and solutions that conserve matter

How we explain it

Children can open this short lesson before they practice.

  1. In a solution, one substance dissolves into another, like salt in water.
  2. A filter separates things that don't dissolve, like sand from water.
  3. Dissolved salt is too tiny for a filter, so heat the water to evaporate it. The salt stays behind.
  4. Cool the vapor and it condenses back into pure water.

Example: How could you get the salt back out of salt water? Salt is dissolved, so a filter won't catch it. Heat the water until it evaporates. The salt is left behind. Answer: evaporate the water

Solutions & Mixtures in Texas

In the Texas Essential Knowledge and Skills (TEKS), this is unit 1 of 15 in 5th grade Science, before Measuring Matter.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Texas Education Agency (TEA)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Kenji has a dry mix of iron filings, sand and salt. Put his separation steps in order.

    • ☕Pour it through a filter to catch the sand
    • ☀️Let the water evaporate to leave the salt
    • 🥄Add water and stir until the salt dissolves
    • 🧲Run a magnet through the dry mix to pull out the iron

  2. Question 2

    Water is called the 'universal solvent.' Why?

    • it can dissolve every substance
    • it is only found on Earth
    • it can dissolve many different substances
    • it never mixes with anything

  3. Question 3

    How could you get the salt back out of salt water?

    ☀️
    • pour it through a filter
    • run a magnet through it
    • stir it faster
    • let the water evaporate

  4. Question 4

    A sieve separates the parts of a mixture by their…

    • temperature
    • color
    • size
    • magnetism

  5. Question 5

    What does solubility mean?

    • how well a substance floats
    • how much of a substance can dissolve in a solvent
    • how fast a substance melts
    • how heavy a substance is

  6. Question 6

    Air is a solution of gases. Which gas is the solvent in air?

    🌬️
    • water vapor
    • nitrogen
    • carbon dioxide
    • oxygen

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