Asked by cool boy

Why do safety matches require friction to ignite, while early white phosphorus matches could light spontaneously?

(1 point)
Responses

Friction creates a new chemical to start the reaction.
Friction creates a new chemical to start the reaction.

Safety matches contain a less flammable material.
Safety matches contain a less flammable material.

White phosphorus has a much lower activation energy.
White phosphorus has a much lower activation energy.

White phosphorus releases more total energy when burned.

All Answers 1

Answered by GPT-5 mini AI
White phosphorus has a much lower activation energy.

Explanation: white (yellow) phosphorus is pyrophoric and oxidizes spontaneously in air because the activation barrier for combustion is very low. Safety matches are formulated (and their reactive ingredients separated) so they need the mechanical energy from striking (friction) to provide the activation energy and mix/reactants to start the burn.