Uploaded February 2021 | Updated September 2026, 2 weeks ago
What’s a fun new way to reuse an old container? Of course – make a cute keychain!
Equipment: used (clean) polystyrene container, whiteboard markers, scissors, letter opener, cutting board, thread, nail polish, oven.
Cut the lid off of a polystyrene container and draw your shape of choice on it. Cut your shape out, make two holes in it with a letter opener, and color it with whiteboard markers. Put it in the oven at 180 °C (360 ° F) for approximately one minute. It should shrink! Now you can put it on a thread and hang it on your keyring – it makes for a cute keychain! If necessary, coat your new keychain with nail polish.
As polystyrene containers are produced, the structure of the polystyrene is changed significantly. The molecules of the polymer are stretched and arranged randomly within its structure (such structures are referred to as “amorphous”), which is what makes it possible to form large pieces of plastic. Heating polystyrene returns it to its original shape: the elongated polystyrene molecules begin to curl up and assume a coil-like form. As a result, the structure of the plastic becomes more ordered, and its rigidity increases.
Amazing and exciting experiments await you in the MEL Chemistry subscription!
Warning! Only under adult supervision.
What’s a fun new way to reuse an old container? Of course – make a cute keychain!
Equipment: used (clean) polystyrene container, whiteboard markers, scissors, letter opener, cutting board, thread, nail polish, oven.
Cut the lid off of a polystyrene container and draw your shape of choice on it. Cut your shape out, make two holes in it with a letter opener, and color it with whiteboard markers. Put it in the oven at 180 °C (360 ° F) for approximately one minute. It should shrink! Now you can put it on a thread and hang it on your keyring – it makes for a cute keychain! If necessary, coat your new keychain with nail polish.
As polystyrene containers are produced, the structure of the polystyrene is changed significantly. The molecules of the polymer are stretched and arranged randomly within its structure (such structures are referred to as “amorphous”), which is what makes it possible to form large pieces of plastic. Heating polystyrene returns it to its original shape: the elongated polystyrene molecules begin to curl up and assume a coil-like form. As a result, the structure of the plastic becomes more ordered, and its rigidity increases.
Amazing and exciting experiments await you in the MEL Chemistry subscription!
Warning! Only under adult supervision.




![Chemical clock
Chemists are so punctual – they’ve even designed a chemical clock!
Hydrogen peroxide is a very active compound and can be both an oxidizer and a reducing agent. In this process, it reduces iodic acid to form molecular iodine and a so-called triiodide complex. This process can be simplified to the following chemical reactions:
HIO₃ + 3H₂O₂ → HI + 3O₂↑ + 3H₂O
5HI + HIO₃ → 3I₂ + 3H₂O
HI + I₂ → H[I₃]
Since oxygen is formed during the first reaction, we can observe the emergence of the gas. The iodine and triiodide complex turn the solution amber. But the solution immediately turns blue, since the starch molecules, which are very long and look like spirals, trap iodine molecules like a fishnet, forming a deep blue iodine-starch complex. Under the action of malonic acid, this complex is destroyed, since it reduces iodine molecules, while the solution itself becomes colorless:
C₃H₄O₄ + I₂ → C₃H₃O₄I + HI
The process repeats every few seconds, and the reaction period depends on the concentrations of the initial solutions. What is this if not a chemical clock?
Fun and safe experiments await you in the MEL Chemistry subscription!
Attention! All experiments are performed by professionals. Do not attempt. Chemical clock](https://i.ytimg.com/vi/ZhBNZV15uy0/mqdefault.jpg)





