How Do Germs Spread?
Do you get told to wash your hands after playing outside or using the bathroom, even when there isn't any dirt on them? Try this experiment to see why you should wash your hands, even if they look clean!
What You Need:
- Hand lotion
- Sink or large bucket
- Paper towels
- A helper
What You Do:
- Put a drop of lotion on your hands and rub them together to spread the lotion out evenly.
- With your hands over a sink or large bucket, have your helper put a pinch of glitter in the palm of one of your hands.
- With your hands still over the sink, make a fist with the hand that has glitter on it, then spread your fingers out. What do you see?
- Now press the palms of your hands together and pull them apart. What do you notice about your hands?
- Touch your helper's hand. Now do you see anything on it?
- Get a paper towel and use it to wipe your hands clean of all the glitter. Is it working?
- After using the paper towel, try using soap and water to wash your hands. Did the glitter come off?
After getting the glitter on your hands, you should have noticed it spreading very easily to anything you touched, even your helper's hand. When you tried to use a paper towel to remove the glitter, some of the glitter probably came off, but most of it stayed on your hands. But when you used soap and water to wash your hands, the glitter came off pretty easily. The glitter is acting the same way that the germs on your hands act - there are a lot of them, they spread around easily, and it can be tough to get them off. The difference is that germs are so small you can't see them without a microscope, so you have to know when you may have come into contact with germs and wash your hands often.
If you accidently touched your mouth, nose, or eyes while doing this experiment, you may have found glitter getting left behind near these areas. Germs travel the same way and can easily enter your body if you touch your face with dirty hands, which can make you sick. That's why it's important to wash your hands before you eat. It is also important to wash your hands after touching something that might have germs, such as when you use the bathroom or play outside. If you don't, the germs can easily spread to more places and to other people and cause sickness.
Germs can be found just about everywhere, but some places have more germs than others. Try this experiment to see where germs are hidden. (Note: This experiment takes a week to complete.)
What You Need:
- An adult helper
- Sharp knife
- 4 Ziplock bags
- Masking tape
What You Do:
- Have your adult helper wash his or her hands, put the gloves on, and then cut the potato in four equal pieces.
- Take the first potato piece and put it in one of the bags. Seal the bag. Use the marker to write on the masking tape and label this bag as 'control.'
- Pick a surface - such as a countertop, sink, or a floor - and while wearing the gloves, rub the second potato piece on it. Place the potato slice in a bag and label it with the surface it was rubbed on.
- Take the third potato piece outside and lay it in a flower bed, a puddle, or something similar. Place the potato slice in a bag and label it with the outside area it was placed in.
- Finally, touch the fourth potato piece all over with your bare hands. Place the potato slice in a bag and label it 'touched with hands.'
- Take all four bags and place them in a dark area at room temperature, like a closet or cupboard. Leave them there for a week. After the week has passed, pull the bags out and look at the potato pieces. (Don't take the potatoes out of the bags.) What do you see on the pieces? Which potato has the most growth on it? Which potato has the least? Why do you think this is?
- When you are done looking at the potatoes, have an adult pour a little bleach into each bag, seal the bags, and then throw them away.
Do you see black, green, or white fuzzy stuff on your potato slices? These are germs, called mold or bacteria, growing on the pieces. The number of germs has grown so large that now you can see them without a microscope (like the piece of bread in the picture). The potato pieces that were handled by you, rubbed on a surface, and placed outside probably had the most growth on them. That's because the potatoes picked up germs from those places. The potato piece that did not touch anything probably has the least amount of growth on it, because it didn't touch anything that had germs. But that potato piece is important, because it lets you see how many germs already existed on the potato. The other potato pieces probably had just as many germs on them from the start, but once they touched other things, the potato pieces picked up more germs and the germs began to grow more than the germs on the first potato.