לחץ כאן לצפיה דרך יוטיוב

This is a classic chemical reaction. It's called the iodine clock reaction. There are several variations of how this chemical reaction can be performed using different chemicals than the ones I used in the video. You can order clock reaction kits from several science related websites. You can also use simple store bought chemicals like vitamin C, iodine, hydrogen peroxide and starch. A quick internet search will turn up multiple ways of performing the experiment.