SATROSPHERE SCIENCE CENTRE
Bending Light Classroom Activities
These materials are designed to help you explore colour and light further in the classroom.
This guide provides examples of activities you can carry out with pupils prior to a visit to
Satrosphere and ideas for ways you can explore light, colour and sight if you have used a
visit to Satrosphere as a starting point to a classroom project. We hope you find these
materials useful. Why not start by determining what pupils already know about light?
Activity 1: The Electromagnetic Spectrum
Have pupils investigate the electromagnetic spectrum and create a diagram or poster similar
to the ones below. Pupils can draw, or cut and paste pictures onto their spectrum to create
examples of each type of wavelength.
Activity 2: Rainbow from White Light
You will need: torch, prism
White light is not actually white but is instead made up
from all the colours of the rainbow. Because the colours
have different wavelengths they will leave a prism at
different angles. By holding a prism in front of white light,
we are able to see the colours that make up the white
light dispersed as they are in a rainbow. Use a powerful
light source and place a prism in front of it so that the
light travels through the prism. Turn the prism (in front
of the light beam) until the colours of the rainbow can
be seen on a nearby table or a wall. It may be helpful to
use a piece of white paper on the table or wall so that you
can see the colours more clearly.
(Prisms can be borrowed from Satrosphere as part of the Colour and Light Loan Box)
Activity 3: Reflected Light Obstacle Course
You will need: torch, prism, mirror, a target
Mirrors can be used to reflect light and so they are another example of a method used to
bend light. Can the children build on Activity 2 and set up a ‘light obstacle course’ with
mirrors and prisms and get the beam of light to reach places around corners and behind
objects?
Activity 4: What colour clothes should I wear…?
We know that thick clothes and lots of layers keep us nice and cosy but does the colour of
our clothes make any difference to keeping us warm or cool?
When you're out in the sun on a hot summer day it pays to wear some light coloured
clothes, but why is that? Experiment with light, colour, heat and some water to find out.
You will need: 2 identical drinking glasses or jars, Water, Thermometer, 2 elastic bands or
some tape, White paper, Black paper, access to sunny spot or a lamp
What to do:
Wrap the white paper around one of the glasses using an elastic band or tape to hold it on.
Do the same with the black paper and the other glass. Fill the glasses with the exact same
amount of water. Leave the glasses out in the sun or under a lamp for a couple of hours
before returning to measure the temperature of the water in each.
What's happening?
Dark surfaces such as the black paper absorb more light and heat than lighter ones such as
the white paper. After measuring the temperatures of the water, the glass with the black
paper around it should be hotter than the other. Lighter surfaces reflect more light, that's
why people wear lighter coloured clothes in the summer, it keeps them cooler.
Try this experiment with pupils as an investigation. Get them to write down what they think
will happen, record their results and hypothesise/discuss in groups what they think the
results mean!
Activity 5: What’s In a Colour? (Chromatography)
The word “chromatography” is derived from two Greek words: "chroma" meaning colour
and "graphein" to write.
You will need:





Chromatography paper or strip cut from a coffee filter.
Chromatography chamber - a small glass jar or cup will do.
Something to lie across jar or cup opening - such as a
skewer, pencil or straw.
A solvent – something to dissolve the ink – try: water,
vinegar, acetone (nail polish), rubbing alcohol, glass cleaner.
Scissors, paper clip or tape, water soluble pens (black
purple or brown work best)
Paper chromatography uses capillary force that moves water or another solvent and the ink
sample up a paper strip. Using chromatography we can find out how many components are
in paint, inks, and pens as well as in natural dyes and leaf extracts. We use the word
“affinity” to refer to the tendency of the dyes to prefer one phase over the other. The dyes
that travel the furthest have more affinity for the solution and the dyes that travel the least
have more affinity for the paper. (The parts of the ink that mix most with the water will
move farther up the paper, those that do not mix with the water will stay closer to the
original ink line.)
What to do: (See diagram above for help visualising set up):
1. Cut a 2cm x 10cm strip of chromatography paper, or cut a strip from a coffee filter. *The
length of the strip depends on the height of the chamber the width does not matter but it
should be able freely get in the chromatography chamber.
2. Wrap one end of the strip around the skewer, pencil or straw and secure with a paper
clip or tape.
3. Draw a pencil line one inch from the bottom of the strip. This is your start line. Draw a
line or dot along the start line with your pen. If instead of a pen you're using paint or
extract put a dot of your sample on the start line using a toothpick.
4. Pour solvent (water or other chosen mixture) into the chromatography chamber (jar)
just to cover the bottom.
5. Hang the chromatography paper over the chromatography chamber, so that bottom of
the strip touches the solvent. *Important! Start line should stay above the solvent!
6. You'll see how solvent "climbs" up the strip dragging the sample with it. Watch colour
going up the strip and possibly separating out into individual pigments.
7. Remove paper from the chamber when solvent is getting close to the paper clip or if it
doesn't move up any more.
8. Repeat steps 1-6 for each available solvent and note the result or simply write solvent's
name on developed paper strip. A good solvent mixture for the black colouring pen may not
work for other substances. You can't identify the chemical composition of your test
substance (colouring pen ink) by paper chromatography, but you can roughly analyze the
mixture with this simple and neat technique.
Activity 6: Mix it up!
You will need: Paint, torches, coloured cellophane, colour paddles.
What happens if you mix colours together?
Get the children to mix up colours of paint. Start with the primary colours: red, blue and
yellow and see what they get, they could make a small chart with the colours they use and
the colour after mixing.
Next, overlap the colour paddles (available in the Colour and Light Loan Box) to see how they
mix. How many new colours can the children make? Can they make up names for their new
colours? Can they match the colours made by overlapping paddles to shades of mixed paint?
The primary colours for light are different to those of materials (i.e. paint). The primary
colours of light are red, blue and green and when you mix these you will get different
colours to those gained from mixing the paints.
Paint
Red + Yellow
Yellow + Blue
Red + Blue
Orange
Green
Purple
Light
Red + Blue
Red + Green
Green + Blue
Magenta (pink)
Yellow
Cyan (turquoise)
Primary colours of light.
The light primary colours are different because the cones in our eyes are the receptors that
see colour and they can only pick up red, blue and green light. They therefore have to mix
these colours together to see the other colours. White light is not actually white! The light is
made up of the colours of the rainbow! Depending on how much red, blue or green is used,
we see different colours.
Cover battery-powered torches with pieces of cellophane to explore mixing colours some
more! Shine them on a white surface and note how the different colours mix together.
Activity 7: Newton’s Colour Wheel
You will need: Colour Wheel Template (found below), colouring pens, pencils or crayons,
tack or tape.
We can also make a disc to show us how colours mix together. There are seven colours in
Isaac Newton's optical spectrum (red, orange, yellow, green, blue, indigo and violet).
Newton himself suggested the use of the colour wheel, in which wedges of paper with the
seven colours on them are pasted onto the surface of a rotating wheel.
To make your own colour wheel, colour in the Colour Wheel Template, starting at the
centre and spreading out to the edge (see Diagram). Cut the circle out and use tape or
tack to secure it to the end of a pencil or pen. Spin the pencil between your palms and
watch the colours on the circle. If spun fast enough, all of the colours will appear to
combine to form white. This occurs because our brain cannot detect and remember the
colours fast enough and so it merges them all together.
Diagram
Colour Wheel Template
Useful Websites
http://www.optics4kids.org/home/teachersparents/articles/color-and-light/
This website is primarily explains the principles of light with some nice activities outlined.
http://www.kidsbuilder.com/FunFactsForKids/light.html
A quick fact sheet on light.
http://www.sciencecompanion.com/wp-content/uploads/2011/04/RainbowColor-and-LightDigital-Sampler.pdf
A pdf of activities that are ready to go.
http://homeschooling.gomilpitas.com/explore/optics.htm
Good, though lengthy videos on optics.