Question

Why does a matchstick burn on rubbing it on the side of the matchbox?

Answer 1

The head of a safety match contains antimony trisulphide and potassium chlorate. The rubbing surface has powdered glass and a little red phosphorous. When the match is struck against the rubbing surface, some red phosphorous gets converted into white phosphorous. This immediately reacts with potassium chlorate in the matchstick head to produce heat to ignite antimony trisulphide and start the combustion.