Question

if a matchstick is struck on a matchbox it catches fire.why?

Answer 1

Here is your answer mate:
A matchstick is a small stick of wood with a solidified mixture of flammable chemicals deposited on one end.When that end is struck on the side of the matchbox which is a rough surface the friction generates enough heat to ignite the chemicals and produce a small flame.

Answer 2

When the matchstick is rubbed against the match box 's side, it catches fire because on one end of matchstick, red phosphorus is mixed with glass and the side of matchbox also contains red phosphorus, when matchstick is rubbed then red phosphorus turns into white phosphorus in the presence of oxygen. Hence, the matchstick catches fire.