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Why do leaves change color?

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WHY DO LEAVES CHANGE COLOUR?

Leaves contain Chlorophyll.  Chlorophyll makes the leaves green and is so dominant that it covers up all the other colours in the leaves. To figure out what colour a leaf would be without the dominant chlorophyll colour, we can separate the colours by doing this science experiment.
This experiment is very simple and you likely already have everything you need:

MATERIALS:

3 leaves (from the same tree)
Rubbing Alcohol
Jar
Plastic baggie (or plastic wrap)
Paper Coffee Filter
Small bowl or pan

STEPS:

1.  Have your child break the leaves into tiny pieces and put in the jar
2.  pour rubbing alcohol over the leaves until they are just covered
3.  mash and stir the leaves into the rubbing alcohol until the alcohol turns slightly green.  Really give it a good mashing – this is key.
why do leaves 3
4.  cover the jar with the baggie or plastic wrap and place the jar in a small bowl and pour hot water into the bowl.
I 
5.  leave (ha!) the jar in the water for 30 minutes, swishing the jar occasionally to stir the leaves a bit.  The alcohol should be a very dark green (leave longer if needed).  If you can resist, wait even 45 minutes or an hour.
6.  Cut a strip in the coffee filter so the strip can reach the rubbing alcohol.  Place it in the jar like this:
Why do leaves change colour science experiment
(We just cut a strip off the coffee filter and taped it to the edge of the jar)
7.  The liquid will travel up the coffee filter and the colours will separate as the alcohol evaporates off the coffee filter.  Let this happen for about an hour for the full effect.  The leaves we used turn to a beautiful yellow in autumn.
colour seperations

SO … WHY DO LEAVES CHANGE COLOUR?

In this science experiment we used the rubbing alcohol and energy (hot water) to separate the colours.  You likely saw green, and depending on your leaf type, maybe red, yellow, or orange.  As we know, Chlorophyll gives leaves their green colour and is so dominant it hides the other colours in the leaves.  But in the fall, chlorophyll in the leaves breaks down allowing the other colours to finally shine through and show their beautiful reds, yellows, and oranges.

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