When we inhale, we breathe in oxygen, and when we exhale, we breathe out carbon dioxide. However, today, in many areas of the world, our air is polluted. This means that when we breathe in we are breathing in polluted air. Do this experiment to find out if the air in your community is polluted or clean.
- Carbon dioxide – the air we exhale after our bodies have used the oxygen.
- Oxygen – molecules in the air that we breathe in to keep our bodies running.
- Set up: 30 min
- Activity: one week to three weeks
You will need:
- Eight natural rubber bands (Most rubber bands are made of real rubber but some rubber bands are not. Your parents or teacher can help you find the right kind of rubber band.)
- Two wire coat hangers or two long pieces of wire that you can bend
- A large plastic bag
- A magnifying glass
- A shady outdoor area where you can hang your experiment
Here’s what you do:
- Bend each coat hanger into a rectangle (or make two rectangles using the wire). If you make rectangles out of wire, you need to make a hook (like a coat hanger hook) at one end of the wire.
- Slide four rubber bands onto each rectangle. Be sure they are stretched tight. You can bend the rectangles out to tighten the bands if you need to.
- Hang one rectangle up outside in the shady place. Be sure it is shady all the time; that is very important.
- Put the other rectangle in the plastic bag. Seal the bag tightly with tape. Keep the sealed bag indoors in a drawer.
- Wait a week.
- When a week is up, check out the rubber bands you hung outside. Look at them carefully with the magnifying glass. Pull on one of them to stretch it. Write down what you see and what happens when you stretch the rubber band.
- Look at the rubber bands you kept in the bag inside. Stretch one of them. Write down what you see and what happens.
- If the rubber bands from outdoors are still in good shape, hang them outside for a few more weeks. Watch what happens to them.
Questions to Answer
If the air in your community is dirty, the rubber bands will break down and come apart very quickly, in just a few weeks. If the air is clean, the rubber bands will eventually come apart but it will take a very long time.
- What did the rubber bands look like after one week?
- What happened when you stretched the rubber bands?
- How were the rubber bands outside different from the ones inside?
- What does this tell you about the air in your community?
- If your air is polluted, what do you think makes it polluted?
- If you don’t know what makes it polluted, how can you find out?
- What can you do to clean up your community’s air?