Science Fenns K-5Grades K to 5
A beam hitting a mirror, a glass of water bending a straw, and a black cloth soaking up light.

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Reflect, Refract, Absorb

Mirrors, lenses and dark cloth.

Lesson 22 of 41

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Before we start

Today’s story

Reflect, Refract, Absorb

A mirror sends a beam back. A glass of water makes a straw look broken. A black shirt gets hot in the sun. Light does three different things.

Reflect means light bounces. Refract means light bends as it enters a new material. Absorb means light is taken in and often turns to heat.

Today we test each one. A mirror, a glass of water and a dark cloth will do it. Here are the steps.

See it

Five steps. Every time.

    Hands on

    Light Lab

    30 minutes · Do this with a grown-up nearby

    You need

    • Flashlight
    • Mirror
    • Clear glass of water
    • Straw
    • Black cloth
    • White cloth
    • Two thermometers

    Do this

    1. Shine the flashlight at the mirror and see where it lands.
    2. Put the straw in water and look from the side.
    3. Lay black and white cloth in sunlight with a thermometer under each.
    4. Wait ten minutes.
    5. Read the thermometers.
    6. Record which cloth was warmer.
    Write or draw: A table with action, material and what you saw.

    Watch for: Which cloth warmed more? Where did the straw seem to bend?

    Safety: Never look at the Sun and keep thermometers out of the mouth.

    Same every time

    Three rules

    Rule 1Match the material to the action

    Shiny reflects, clear refracts, dark absorbs.

    Rule 2Watch the beam

    Light shows what it does.

    Rule 3Be careful with strong light

    Never look at the Sun.

    Grandpa Fenn’s notebook

    Say it like a scientist

    reflect
    To bounce back.
    refract
    To bend when passing into a new material.
    absorb
    To take in.
    lens
    A curved clear piece that bends light.

    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 light was absorbed?
    • Where do you see these three at home?
    Did you know

    Rainbows form because raindrops refract and reflect sunlight and split it into colors.

    Someone who does this

    An optician designs lenses that bend light to help eyes focus.

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