This experiment demonstrates the difference, in the pulling power of water and alcohol.
Things Required:
1-foot sheet of aluminium foil food
Colouring (red or blue)
Rubbing alcohol
Water
Eye-dropper
2 cups
Directions:
Add enough food colouring to 1/2 cup of water to make a dark solution. Fill a second cup one-quarter full with alcohol. Smooth the sheet of aluminium foil on a table. Pour a very thin layer of the coloured water onto the foil. Note: The thinner the water, the better.
Use the eye-dropper to add a drop of alcohol to the centre of the thin layer of coloured water.
This Is What Happens:
The water rushes away from the alcohol leaving a very thin layer of alcohol on the foil. The water is pulling and this causes a pulsation around the edges of the alcohol.
Science Behind It:
The water molecules on the surface of the water are pulling equally in all directions before the alcohol is added. When the drop of alcohol touches the water there is an immediate separation between the two liquids. Alcohol is pulling away from the water and the water is pulling away from the alcohol. The water molecules seem to be victorious and the water spreads outward taking some of the alcohol with it. This outward movement causes the alcohol to be spread into a thin layer over the foil. It also causes the water molecules to stack up and form a ridge around the alcohol layer. This ridge has a pulsating motion because the water and alcohol molecules continue to pull on each other. The pulling stops when the two liquids totally mix together.
