The importance of washing your hands...

Does washing your hands really make a difference to germ control? 

This is what we found out... 

If you place your finger, which is lathered in soap into the water, you'll notice that the soap particles expel (remove) the black pepper from the area surrounding your finger. 

This happens because soap is able to break down the surface tension of water (it's what makes soap such a good cleaner!). As the soap moves into the water, the surface tension changes, and the pepper no longer floats on top. The water molecules still want to keep the surface tension going, so they pull back away from the soap, and carry the pepper along with them.  

We wondered... 

Does it make a difference if the water is hot or cold? What happens if you try out different substances other than soap? Does anything else have the same effect? Try this out at home ( please make sure you ask an adult first!).