Science Fenns K-5Grades K to 5
A tray of sand and iron filings with a magnet pulling the filings out in a spiky cluster.

Science / All lessons / Matter and Particles

Mixtures Keep Their Parts

Iron filings and sand. Sand and water.

Lesson 11 of 41

Try this first

Before we start

Today’s story

Mixtures Keep Their Parts

Pour sand into a pan of iron bits. Each stays what it was. The sand is still sand. The iron is still iron.

This is a mixture. The parts of a mixture keep their own properties. That is why you can often separate them again.

We can use a magnet, a sieve, a filter or just water. Which tool works depends on the properties of the parts.

See it

Five steps. Every time.

    Hands on

    Separate the Mix

    30 minutes · Do this with a grown-up nearby

    You need

    • Sand
    • Iron filings or steel wool bits
    • Magnet in a plastic bag
    • Cup of water
    • Coffee filter
    • Second cup
    • Tray

    Do this

    1. Mix a spoon of sand with a spoon of iron filings.
    2. Pass the magnet in the bag over the mix.
    3. Tap the bag over a clean tray to release the filings.
    4. Stir sand into water and watch it settle.
    5. Pour through the filter into the second cup.
    6. Draw what you see at each step.
    Write or draw: Drawings and notes for each method with how well it worked.

    Watch for: Did the sand keep its look? Did the filings?

    Safety: Keep iron filings out of eyes and mouth and wash your hands after.

    Same every time

    Three rules

    Rule 1Use a property to separate

    Choose a tool that fits the property.

    Rule 2Check your result

    Look at each pile after.

    Rule 3Keep the parts

    Mixing is not changing.

    Grandpa Fenn’s notebook

    Say it like a scientist

    mixture
    Two or more things together that keep their own properties.
    separate
    To pull apart.
    filter
    A tool with tiny holes that catches bits.
    property
    A feature used to describe matter.

    Poppy’s quiz

    Six questions

    Tap an answer. Green means right. You will see why.

    Talk about it

    Say it out loud

    • How do you know the parts kept their properties?
    • What mixtures do you see on a farm, like feed or soil?
    Did you know

    Panning for gold works because gold is denser than the sand and settles to the bottom.

    Someone who does this

    A recycling plant worker uses magnets to pull steel cans from a pile of trash.

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