Have you ever wanted to bring your pictures to life? Here’s one neat trick to make a drawing float away, literally!
* Hint: The activity works best if the bowl is quite new, without cracks or scratches.
Draw a small picture in the bottom of the bowl with the whiteboard markers.
Tilt the bowl to the side and add about a tablespoon of water, away from the drawing.
Slowly tilt the bowl back so the water starts to touch the edge of your drawing. The marker ink will start to float up to the surface of the water.
When it’s completely floating, you can move the drawing around by gently shaking the bowl, by blowing on it, or by poking it very gently.
Whiteboard marker ink has three main ingredients. Pigments give the ink colour and solvents keep it liquid inside the pen. The third ingredient is a resin, which is need to make this activity work.
Whiteboard marker resin is an oily solid, which sticks lightly to whiteboards. Inside the marker, the resin is dissolved in the solvent chemicals. After you’ve drawn a line, the solvents quickly evaporate and the resin turns back into a solid.
When you add water to the bowl in this activity, you start a struggle. The resin sticks to the bowl like it would a whiteboard. But it also sticks to the surface of the water. The attraction force of the water surface, known as surface tension, is strong enough that you can use the surface of the water to peel the marker off the bowl.
Surface tension is surprisingly strong. In a recent experiment, scientists from the United States and France used surface tension to peel permanent marker off a sheet of glass!
If you’re after more science activities for kids, subscribe to Double Helix magazine!
7 April, 2020 at 6:01 am
I tried it but it barley worked. It kept coming apart. Do you have a solution for me?
7 April, 2020 at 9:22 am
Hi Rachel,
I’m sorry to hear it’s not working well for you. The images can break up, especially if the whiteboard markers are a bit old or they’re running out. Sadly, I’m working from home at the moment, and I don’t have whiteboard markers here to test with. But the darker the lines you draw, the better it should hold together – so draw slowly and softly, with thick lines, and maybe even try drawing over it again softly after it has dried?
Sorry I couldn’t be more helpful,
David