Danger! Explosion - Spontaneous Bromination

The Experiment:

Our assistant, Christian, poured 5 ml bromine - a brown liquid - into a glass cylinder and added a piece of aluminium foil. In order not to breathe in any bromine, we conducted the experiment in a fume hood behind a glass screen and all of us wore safety goggles.

The bromine reacted very vigorously with the aluminium foil: After a few seconds red and green sparks were coming out of the cylinder like fireworks and yellow-brown smoke developed, which vanished very quickly. We tried the experiment three times, because we liked it very much.

The Explanation:

Bromine is an element of the 7th main group and belongs to the halogens. It reacts very easily and forms chemical compounds with many elements. Aluminium is in the 3rd main group. The further away the elements are from each other in the periodic table, the more intensely they react, as this experiment has shown very well.

Aluminium is used for the production of fireworks and explosives. In the open air, finely dispersed aluminium burns to aluminium oxide by emitting flashes of light and a lot of heat.