Watch this science video tutorial from Nurd Rage on how to make a test tube thunderstorm. They show you how to make the thunderstorm in a test tube using alcohol, sulfuric acid and potassium permanganate.
WARNING: This experiment is extremely dangerous as it involves corrosive acids and flammable liquids with a small, but not negligible, chance of a damaging explosion. Face shields, goggles, fire extinguishers and fire safety protocols must be present. This should only be attempted by an experienced chemist.
Just get a test tube of 95% alcohol and carefully pipette a layer in a bottom of sulfuric acid. Then drop in some potassium permanganate crystals. It takes about a minute to start up.
The reaction of the permanganate and the sulfuric acid produce manganese heptoxide that explodes on contact with organic matter like the alcohol. This also works with acetone.
Brought to you by one of WonderHowTo's favorite scientists NurdRage.