A very simple experiment to do at home is with tonic, specifically Schweppes brand tonic. Schweppes tonic (the traditional yellow bottle) is fluorescent. I don't know if other brands of tonic are also fluorescent.
Fluorescence is the phenomenon whereby an atom emits light when irradiated with ultraviolet light. There is also chemical fluorescence which occurs when 2 chemicals are mixed together. This second case would be the case of fluorescent bracelets and party sticks.
Ultraviolet light can be obtained with simple torches, which you can get on amazon, for example here: ultraviolet light torch.
It is quite striking because it
The tonic is completely transparent and the last thing you expect when illuminating it with ultraviolet light is for it to radiate light.
VIDEO EXPERIMENT
TECHNICAL EXPLANATION
The component in the tonic that makes it fluorescent is Quinine, which can be seen in the list of materials on the back of the tin. Quinine is a natural component, formerly known for its healing properties. Very interesting information about quinine, you can read more on wikipedia, here: quinine.
WOULD YOU ALSO LIKE TO MAKE A FLUORESCENT LIQUID?
In this post we explain how to to make a fluorescent liquid.