Easy science tricks for school
Amaze your classmates with simple science tricks!
Warning! Only under adult supervision.
- regular erasable pen;
- sheet of paper;
- yellow highlighter;
- cotton swab;
- large baking dish;
- pen or cocktail straw.
Write something on a sheet of paper with an erasable pen and heat it for a short time – the inscription disappears! It will reappear if you leave the paper in the freezer. If you suddenly outlined the wrong text with a highlighter, don’t worry: cut a lemon and soak a cotton swab in the juice. Then apply it to the outlined text – the yellow color disappears! Disassemble a pen, leaving the hollow body (a cocktail straw will also work). In a large baking dish, prepare a soapy solution so that there is some foam on top. Inflate a balloon and attach it to the pen’s body – now you can write on the surface of the solution with soap bubbles!
Erasable pens usually have three components. When heated, the bonds between them change, causing the color to fade. The process can be reversed by cooling the former inscription. Yellow highlighter ink contains a pyranine dye. Its color is sensitive to acidic media. Lemon juice contains citric acid, which easily fades pyranine! Bubbles from ordinary water are unstable – they quickly burst due to the water’s surface tension. But this surface tension can be lowered with soap! If there is also a little foam on the solution’s surface, the bubbles will remain stationary. Now you can write with soap bubbles!
Enjoy even more science tricks with the MEL Science subscription!!