Science for kids is one of our favorite topics, and this science activity is a fun one! Kids will have fun predicting how many paperclips they can fit in a full glass of water, and actually trying it out for themselves. This science experiment exploring the surface tension of water always seems to surprise the kids!

Welcome to another invitation to explore science! Last week we had fun with Dancing Raisins! This week we are going to explore the surface tension of water. It’s an experiment that’s sure to inspire a sense of wonder and curiosity in your child! (This post contains affiliate links. Thank you so much for your support!)

Are you following our Science for Kids Pinterest Board?

Science for Kids: Exploring the Surface Tension of Water with Paperclips

Materials

• Clear glass
• Water
• Dropper or pipette
• Lots of paperclips

Procedure

1. Fill your glass of water as high as you can without it spilling.
2. Then use a dropper or pipette to add the last few drops, so it’s as full as you can possibly get it. 
3. Have your child estimate how many paperclips he or she thinks will fit into the glass before the water overflows.
4. Begin dropping the paperclips in one at a time. Older kids may want to keep track of how many they’ve dropped in as they go along. You could arrange your paperclips in piles of tens to keep track easily.
5. Keep going until the water finally overflows.

 Tips

• Set this up on a table that can get wet. There’s sure to be some spills, especially with little ones.
• Even toddlers can get in on the action! Theo wanted to do what his big sister was doing. I put some water in cup and gave him some paperclips. He had lots of fun dropping them into the cup!

Question to Spark More Curiosity & Critical Thinking

How close were you to your estimate? Why do you think so many paperclips were able to fit in the glass?

Here were some comments I caught Lucy making during the experiment: “Why is it not spilling?” ” I think it’s because they’re so tiny.” ” Look how much paperclips are in it!” ” Why don’t the paperclips float?” ~So much thinking going on!

What’s Going On?

Drops of water stick to each other. That’s why the surface of the water bulged and formed a dome when you added the paper clips, which kept the water from spilling out. This is called surface tension. Once too many paperclips were added to the cup, the surface tension was broken, allowing the water to spill over.

Want to go even further?

Even more activities to inspire creativity and critical thinking for various ages. 

• Try this experiment using something other than paperclips. Were the results similar or what you expected?
• Devise ways to easily keep track of counting the paperclips. (Ex. tally marks, number chart etc.)
• Make a list of more questions that you thought about as you did this science activity.
• Try a similar experiment. See how many drops of water can sit on the surface of a penny using a dropper. Was it what you expected? 
• Related book:  A Drop Of Water: A Book of Science and Wonder 
  

 Be sure to also check out:

Exploring Surface Tension

Create a Marble Run

Turn a Penny Green