Supplies Needed:
• Spray bottle
• Water
• 1 teaspoon sugar
• Loaf of bread
• Sandwich baggies
• Permanent marker
The Experiment:
Fill the spray bottle with water, add the sugar and shake the bottle until the sugar dissolves. Wash your hands and grab a piece of bread from the loaf. Spray it one time with the water. Then wipe the wet side if the bread on a surface in your house. Try the inside of your fridge, a doorknob, the inside of the kitchen sink, the toilet seat, etc. After you wipe a piece of bread on a germ source, drop it into a sealable baggie, seal it and use the marker to label the bag.
Put the baggies in a dark place to be undisturbed for a couple of days.
The Outcome:
The germs from the wiped surfaces stuck to the bread and became food for the mould on the bread.
Variation:
Cleaning is important! Wipe a germy area with the bread and bag it. Then clean that surface and do a second bread wipe and bag it. A few days later, compare the two bags. How effective was your cleaning?
Try this:
To remove germs when you wash your hands, you should wash for 20 seconds. Think of a 20-second chorus and make that your “handwashing song”.
Tip:
Have an experimental control group: spray one piece of bread then immediately put it in a baggie without wiping it on anything.
Source: The 101 Coolest Simple Science Experiments by Rachel Miller, Holly Homer and Jamie Harrington.