Defy gravity and show your students some magic by performing this drops of water on a coin science experiment. We added an extra dimension to this classic 5 minute science experiment by comparing how many drops of water fit onto each coin (penny, nickel, dime, and quarter) and tracking the data on a table to add a more mathematical and scientific element to it.

Gather up some spare change for this drops of water on a coin surface tension experiment! An easy science experiment for kids with a free printable chart.

Getting Ready

*This post contains affiliate links. Please see our disclosure policy.

I started this experiment by placing one of each coin (penny, nickel, dime, quarter) on a paper towel and asking the kids which coin they thought would hold the greatest number of drops of water. They each made a hypothesis, or an educated guess.

I printed out the chart available for free below so we could keep track of our results. Armed with a pencil to write with, a plastic pipette, and a cup of water, the kids were ready to begin.

Gather up some spare change for this drops of water on a coin surface tension experiment! An easy science experiment for kids with a free printable chart.

Drops of Water on a Coin Experiment

The kids followed these instructions to complete the drops of water on a coin experiment:

  • Set the coin on a flat surface.
  • Fill a plastic pipette with water.
  • Carefully squeeze out water drop by drop from the pipette onto the coin. Count how many drops fit on the coin before the dome breaks and the water spills over.
  • Keep track of the results on the printable chart, available below. Repeat three times for each coin and then calculate an average in the last column.

What were the results? Which coin held the most drops of water? Was the hypothesis correct? Why or why not?

Surface Tension Explained

So why does a dome form when water is dropped onto the coin? And why does the dome eventually collapse?

Gather up some spare change for this drops of water on a coin surface tension experiment! An easy science experiment for kids with a free printable chart.

The answer to this lies in the structure of the water molecule itself. Water is a polar molecule, meaning that it has a positive end and a negative end. The negative end of one molecule is attracted to the positive end of another molecule (similar to a magnet), which makes the molecules stick together tightly. The molecules on the surface are pulled inward and they stick together so strongly that they form a dome. This is called surface tension. Eventually, though, gravity overcomes this force and the dome breaks, spilling water over the sides of the coin.

Download a free printable chart to keep track of the results by clicking below:

For another fantastic (and colorful!) surface tension activity check out our magic milk fireworks! The kids will LOVE it.

Gather up some spare change for this drops of water on a coin surface tension experiment! An easy science experiment for kids with a free printable chart.

This post is part of the A-Z STEM Series. Every day during the month we will be bringing you tons of awesome science, technology, engineering, and math activities to do with your kids! By the end of the month you’ll have over 50 STEM activities to keep your kids busy learning.

Gather up some spare change for this drops of water on a coin surface tension experiment! An easy science experiment for kids with a free printable chart.

More Hands-On Fun for Kids –>

These jaw-dropping kitchen science experiments will wow kids from preschool on up! A collection of more than 20 experiments to do at home or at school.
Calling all LEGO lovers! Put your engineering skills to work, build a LEGO maze, and get your hands on over 100 ways to learn and play with LEGO bricks!
Making a Skittles rainbow is a quick and easy kitchen science experiment that will thrill the kids and engage their creativity. STEM for St. Patrick's Day.
A year’s worth of captivating STEAM (Science, Technology, Engineering, Art & Math) activities that will wow the boredom right out of kids!

Receive a FREE Science Packet by Entering Your Email Address Below



STEM Saturday

DIY Rocket Building Station for Kids from Lemon Lime Adventures

Pool Noodle Structures for Kids from Little Bins for Little Hands

Butterfly Math Grid Game from Stir the Wonder

By | 2017-08-17T21:44:00+00:00 April 23rd, 2017|Five Minute Science, Science, STEM Saturday|9 Comments

9 Comments

  1. Eileen Teo January 22, 2015 at 2:03 pm - Reply

    This is fun! Going to do it with my kids later today! Thank you for sharing it with us #pintorials

    • Crystal January 25, 2015 at 3:03 am - Reply

      AWESOME! Have so much fun 🙂

  2. Samantha January 24, 2015 at 1:45 pm - Reply

    Wow! This looks like a pretty cool experiment!

  3. Lisa Nelson January 24, 2015 at 6:47 pm - Reply

    This is an awesome experiment! What fun! I love fun and easy experiments. I am definitely sharing this on my STEM board. Thanks so much for sharing!

    • Crystal January 25, 2015 at 3:04 am - Reply

      Thank you for stopping by and for sharing!!

  4. Trish Corlew January 27, 2015 at 5:30 pm - Reply

    Thanks for sharing your article on the Hip Homeschool Moms Hop. I chose it as my favorite article from last week’s Hop, so you are featured on this week’s Hop! Don’t forget to stop by and grab your “I was featured on Hip Homeschool Moms” button! Your article has also been added to our Science Board on Pinterest 🙂 We are looking forward to seeing more articles from you in the future!

    • Crystal January 29, 2015 at 6:13 am - Reply

      Thank you so much, I am so honored! And I was so touched by what you said on the featured article about hands-on activities and my website 🙂 I love stopping by the Hip Homeschool Hop every week to see what is new.

  5. Susen Kuchta March 8, 2015 at 11:53 am - Reply

    Just popped over to this experiment after reading your Magic Milk……have to try this one too!!

Leave A Comment