The intention of all this effort is to view the outreaching effect of a small amount of pollution on a stream and its wildlife.
Things Required:
1 gallon (4 litre) glass jar
Measuring cup (250 ml)
Red food colouring
Directions:
Pour one-half cup of water into the gallon (4 litre) jar. Add and stir in two drops of food colouring. Add one cup of water at a time to the jar until the red colour disappears.
This Is What Happens:
It takes about 7 measuring cups of clear water to make the red colour disappear.
Science Behind It:
The red is visible at first because the molecules of red colour are close enough together to be seen. As clean water is added, the colour molecules continue to spread evenly throughout the water. They finally get far enough apart to become invisible because of their small sizes. This is what happens with some water pollutants. The material may be visible where it is initially dumped, but as it flows downstream and becomes mixed with more water it is no longer seen with the naked eye. This does not mean that it is gone. Just like the red food colouring, it is still in the water and you would be ingesting small quantities if you drank the water. Similarly, animal life in the stream is affected by pollutants many miles from the source.
