When Will it Spill?

Water has a unique property called “surface tension”. To find out what this means, try the experiment below!

Here’s what you need:

  • Clear glass
  • Paper clips
  • Water

Now here’s what you do:

  1. Fill the glass with water until it’s completely full
  2. Now predict how many paper clips you can put into the glass until the water spills out.
  3. Start placing the paperclips into the glass – make sure to count them as you put them in.
  4. How many can you place in the glass before it overflows? How close was your guess?

What did you learn?

The cup can hold hundreds of paper clips before it overflows! That’s because water has “surface tension”. The water forms a thin skin, a surface on top of the water. If you bend down and look at the glass, you’ll see the water rise on the top, but not spill out. That surface tension keeps the water from spilling out of the glass.