Easy science tricks for school

Amaze your classmates with simple science tricks!

Warn­ing! Only un­der adult su­per­vi­sion.


  • reg­u­lar erasable pen;
  • sheet of pa­per;
  • freez­er;
  • yel­low high­lighter;
  • lemon;
  • cot­ton swab;
  • large bak­ing dish;
  • soap;
  • wa­ter;
  • bal­loon;
  • pen or cock­tail straw.

Step-by-step in­struc­tions

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!

Process de­scrip­tion

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!!