Flash paper can help illustrate how combustion is dependent on proximity to heat

https://padlet.com/chelenzcqn/bookmarks-77mdkw1tm4j27vxg/wish/PVKBQOrLB5vNaj5x

Flash paper can aid illustrate how combustion depends on proximity to warmth. Bringing the flame nearer speeds ignition, whilst getting rid of it ends the burn hastily.