This solar energy kids experiment is aimed at understanding the different heat absorbing capacity of different colours backgrounds and the effect of those on the melting rate of ice cubes.
** 6 different coloured square pieces of card or paper. Black and white are essential, and any other 4 colours will do (the three primary colours red, blue and yellow, as well as green are good choices for the other cards). Make the squares about 7cm x 7cm (3 inches x 3 inches).
** 6 ice cubes of the same shape and size
** food dyes (optional)
Put one ice cube on each card and place them all in the sun. Make sure all the ice cubes are exposed to full sunlight. See which one melts the fastest, which melts the slowest.
What Will Happen?
The black card or ice will melt fastest as it absorbs the most light; it is the most efficient Solar heat collector. The white will melt the slowest since it reflects most of the light. The other colours absorb all the light EXCEPT the ONE they reflect; this is the colour they appear to us.
Another option is to make coloured ice using food dyes. For the white block I suggest adding milk to the water and for the black one mix up all the other colour food dyes; it won’t be quite black but it will be close enough. Other options for the black block could be cola. This variant will have a lot more interest for your child as they also get to prepare the ice. For this variation, use white paper or card as the substrate.
Combine Both Tests:
Why not combine both the coloured cards and the coloured ice blocks and compare the results! Both these activities together will take a young child at least an afternoon to complete. And while she’s outside watching the ices melt, you might even get a break…
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