Experiments with KVRR Meteorologist Scott Sincoff: Penny Water Drops

Fun, Easy, Kid-Friendly Science Experiments

This week, Meteorologist Scott Sincoff conducted the science experiment, Penny Water Drops.

Here’s what you need for the experiment:

• Cup of Water
• Pennies
• Paper Towel
• Water/Medicine Dropper or Pipette

Here’s how you conduct the experiment:

• Wash and rinse a penny in tap water. Dry it completely with a paper towel.
• Place the penny on a flat surface. The flatter the surface, the better this experiment is going to go.
• Use an eyedropper or pipette to draw up water.
• Carefully, drop individual drops of water onto the flat surface of the penny.
• Keep track of the water drops as you add them, one at a time, until water runs over the edge of the penny.

The scientific explanation:

There are two properties at work in this experiment: cohesion and surface tension. Cohesion is the attraction of like molecules to one another. Hydrogen bonds are formed by the hydrogen atoms of one molecule being attracted to the oxygen atoms of another molecule. In this case, the like molecules are the H20 molecules in the water drops. The bubble shape is a result of the water molecules clinging to one another in an optimal shape.