Penny Lab Experiment

I conducted an experiment involving penny, soap and water.

PART A:

RESEARCH QUESTION:

How many drops of water can you fit on a penny before it spills?

HYPOTHESIS:

If you put 10 drops of water then it would not overflow because of the water’s cohesion.

MATERIALS:

-Water

-Eyedropper

-Penny

METHOD:

1. Rinse a penny in tap water and dry completely
2. Place the penny on a paper towel
3. Use the eye dropper to place drops of water on the penny (one at a time) until any amount of water runs off the penny

OBSERVATIONS:

Trial 1	Trial 2	Trial 3	Trial 4	Average
19	16	18	20	18

PART B:

RESEARCH QUESTION:

How many drops of water, after the penny has been dipped in soap, can fit on the penny?

HYPOTHESIS:

If you put 10 drops of water then it would not overflow because of the water’s cohesion.

MATERIALS:

-Water

-Eyedropper

-Penny

-Soap

-Tweezers

METHOD:

1. Clean the penny by rinsing it under tap water
2. Dry it completely
3. With tweezers, dip the penny into the soap
4. Place the penny on a paper towel
5. Place drops of water on the penny until any amount of water runs over the edge of the penny

OBERVATIONS:

Trial 1	Trial 2	Trial 3	Trial 4	Average
7	5	FAIL	6	5

CONCLUSION:

My hypothesis was incorrect. It turns out you can fit around 18 drops of water on a normal penny and 5 drops on a penny dipped in soap.

When we did this experiment, I noticed that once the drops go on the penny it turns into 1 bigger drop. It looked like a bubble. But when the penny was dipped in soap, the drops would not stick together as much, and once the drops just slid off the penny entirely. This is because soap cuts down the cohesion.

If I did this again, I would want to make sure the penny is the same level throughout and make sure it doesn’t hav