“Gallium heart” experiment
How to bring gallium to life
Metals are often associated with something solid and indestructible. But despite the stereotype, this metal will tremble as soon as solutions touch it.
Wear protective gloves and glasses.
Warning! Only under adults supervision.
Reagents and equipment:
- gallium (5 g);
- 20% sulfuric acid solution (20 ml);
- 10% potassium dichromate solution (2 ml);
- porcelain cup.
Melt gallium in hot water and put it in a porcelain cup. Then pour the sulfuric acid over the drop of gallium and add the potassium dichromate solution drop by drop. The gallium starts to throb. Over time the throbbing stops. Add a new portion of potassium dichromate–and the drop will tremble once more.
Gallium is a metal which turns liquid at 29.8 °С, so it can even melt in the hand. When it reacts with sulfuric acid, it becomes covered with gallium(III) sulfate. The surface tension of the drop increases, and it contracts into a ball. When potassium dichromate is added, oxidation-reduction processes take place, which have still not been fully explained by scientists. As a result, the film of gallium(III) sulfate disintegrates, the surface tension decreases, and the drop spreads out. The process repeats until all the potassium dichromate runs out.