How do germs move around us?  Why do so many people catch colds and other illnesses?  Our bodies are designed to keep us as healthy as possible.  However, germs are all around us and by understanding how they work and how our bodies work to fight off these germs, we can take better care of ourselves and those around us and live healthier lives.

Experiment #1

Peppery Germs

Fill a small dish with water.
Sprinkle pepper on top of the water.
Have one person dip their finger (just one) into the “pepper water”.
What happened?

Now, take a small amount of dish soap and dip a finger into the soap.
Take the same finger that has the soap on it and dip it back into the “pepper water”.
What happened?

The Science Behind the Experiment

Why does the pepper float?  Why didn’t it sink or dissolve in the water?

Pepper is hydrophobic. This means that the pepper repels water and since it repels, it cannot dissolve.  It floats because molecules prefer to stick together and when they do stick together, it creates Surface Tension.  Because the pepper is so light, the surface tension makes it float on top of the water.

Why does the pepper run away from the soap?

The soap breaks the surface tension of the water which makes the pepper repel the soap. As the soap enters the water and mixes with the water the pepper will no longer float on the water.  The water molecules want to stay together so the water instantly repels against the soap and moves in the opposite direction and it carries the pepper along with it.

Experiment #2

Germy Bread Experiment

Label each of the bags:

1. Control – Carefully place the Control slice of bread into the bag without touching it and seal it.
2. Dirty Hands – Have the children touch the bread without washing their hands. Place it into the baggie and seal it.
3. Washed Hands – Now, have the children wash their hands using soap and water. Now let them touch the third slice of bread and then place it in the bag and seal it.

Place the three bags in a cool dry place to observe changes for the next week or so. Observe the bread each day and notate your findings. You can even keep a photo diary over the course of the week to compare the unique differences in the bread.

Which bread molded first?
How does the mold grow? In spots or connected as one piece of mold?
Which bread grows the most mold?
Which grows the least?

The Science Behind the Experiment

Bread gets moldy because it provides a good source of food for some types of fungus. The air is filled with tiny mold spores and they settle on organic substances and then will start to digest the substance. In bread, the mold enzymes break down the cell walls of the bread creating the mold that grows on the bread.

Bacteria and other forms of germs from our bodies (skin and airborne germs) offer the mold a bigger food supply, so it will make the bread mold more rapidly. So, the more germs added to the bread, the faster it will mold.