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Science Rocks!

Drops on Pennies


your results

Sent in by:
Amber of South Amherst, OH

The pennies are back with added change for an added challenge.

Materials Needed

  • different size coins like a penny, quarter, nickel, or dime
  • paper towels
  • water dropper
  • water in a cup
  • paper and a pen or pencil to keep track of your data



  1. How many drops of water can you fit on a penny? How about a quarter? Make a prediction. Start by putting one drop of water on a penny. Now, how many more do you think it can hold? Why?
  2. Keep adding drops to see how your prediction turns out. Remember to keep track of your data. Do it three times and then figure out the average number of drops that can fit on a penny.
  3. Next, try it with a quarter. Make a prediction.
  4. Use what you know about how many drops of water the penny held.
  5. Keep adding drops to see how your prediction turns out. Do it three times and then figure out the average number of drops that can fit on a quarter.
  6. Compare the number of drops the penny held to the quarter.

Now it's time for you to experiment. Think of a question that you want answered. Like, do all pennies hold the same amount of water? What other things besides size affect the number of drops each coin can hold? Write down what you thought was going to happen and what did happen. Then test out your question and send your reports in to our special feedback area. Every week, we'll publish a whole bunch.

Some of your Results

Michelle, age 12 of New York City wrote:
when I did it I got about 20 drops on the pennies I waz awsome

Morgan, age 11 of Victoria, TX wrote:
i got 45 drops on one little penny!!! WOW!! isn't that amazing

Sandy, age 12 of Glen Oaks, NY wrote:
For some reason the quarter has less drops than the nickel. I was so off on my results. But I loved the project.

Harjinder, age 11 wrote:
When I did this expirment I got upto to 83 drops of water on it!!! now I am trying it with other coins

Evelyn, age 13 of Las Vegas, NV wrote:
when I did this science experment I was very surprise of the results I got! what I had predicted is that 5 drops will fit on a small penny. I now no that 27 drops fit on a PENNY!!! thanxs for this idea!:]

Mercedes, age 13 of Berwyn, IL wrote:
well, I did this when I was in 7th grade and I got 68 drops of water to go on the pennies and then the bubble poped. But other classmates got up to like 73 drops of water.

Daisy, age 12 of Melrose Park, IL wrote:
I did the expieriment man it was so much fun! I used a penny. And I did it ten timesbut then, the water fell.

Carolina, age 12 of San Antonio, TX wrote:
If you drop the drops on the heads' side of the penny you will have less roon for the water to join together. If you have it on the tails' side you will have more room for the waterto join together and it will have more drops being held than the head side!!

Amber, age 11 of Mansfield, MA wrote:
I found that a penny could hold an average of about 27 drops of water.

Grady, age 7 of Louisville, KY wrote:
I was aele to put 8 drops on one penny.

Alaina, age 10 of Hueytown, AL wrote:
The highest number in drops I produced was 71 in quarters. This science project was so great! My predictions were so off!

Kelsey, age 10 of Hueytown, AL wrote:
Hi my name is Kelsey. The nickel held the most. It held 42 drops of water. My predictions were really off. My predictions were around 8-20 drops of water.

Austin, age 10 of Hueytown, AL wrote:
My surface tension predictions were kind of close. I got 158 for the total number of drops on the nickel and 128 for the quarter. 71 for the total on the pennies and 90 for the dime. I really loved doing this experiment.

Dylan, age 10 of Hueytown, AL wrote:
The quarter didn't hold as much as the nickel. That was interesting because the quarter is the biggest. Out of all my guesses the quarter was the closest. My guess was 21 drops, it held 20 drops. The rest of my guesses were way off. Surface tension is very interesting.

Paige, age 10 of Hueytown, AL wrote:
Hi my name is Paige and on this project I got 78 drops of water on my penny in all, on my nickel I got 144 in all, on my dime I got 97 in all, and on my quarter I got 143 in all. I don't know how that happend but, my nickel is more than my quarter. My predictions were close on some trys and way off on others. But, I would like other people to try this project and you can do it with other materials...

Johanna, age 10 of Hueytown, AL wrote:
All of my predictions were way off. The hightest test run was sixty-eight on the quarter on the third test. I was not expecting the dime to hold thirty-two drops. I had lot's of fun doing this experiment!!!

Hayden wrote:
Water built up when I put it on a coin, that is called surface tension. Here are my highest scores: penny-30/ nickel-49/ dime-18/quarter-30. I loved this experiment because it was very exciting. My predictions were okay.

Nicholas, age 8 of Hueytown, AL wrote:
My best test is 41 on a quarter!!!

Peyton, age 9 of Bessmer, AL wrote:
I like the part where the surface tension looked like a dome. I got 22 on the penny. This is amazing!

Jake, age 8 of Forestdale, AL wrote:
I wish you had fun on this experiment. I did. My favorite part was the quarter. It was fun because I got 61 on it! The surface tension was really fantastic! Well hope you had fun.

Josh, age 9 of Hueytown, AL wrote:
My best total with the nickel and quarter was 84.

Douglas, age 9 of Hueytown, AL wrote:
The total of the drops on a quarter was 69. The average on the quater was 23. On a total of a dime was 29 on my first try.

Ariana, age 8 of Hueytown, AL wrote:
When I tried it I got a huge! amonte my best test was a. Quarter I thoght Icould get twety but insted I got a total of sixty six! I was suprised to! So when you try it have a great time!

Diana, age 8 of Hueytown, AL wrote:
My favorite one was the nickel becase I got thrty two drops on the nicke

Alexis, age 11 of TX wrote:
I got 30 penny drops.

Kai, age 5 of Lake Forest Park, WA wrote:
penny dry: 22 drops /wet: 15 drops nickel dry: 29 drops / wet: 23 drops quarter dry: 37 drops /wet: 23 drops

Jayjuan, age 8 of Petersburg, VA wrote:
I got 60 drops on a silver dollar before any spilled off.

Ryan, age 11 of New York City, NY wrote:
I got 159 drops only on a one dollar coin.

Alex, age 12 of Loveland, OH wrote:
I got 52 drops on my penny.

not yet implemented