[paul.fr]

Flares, they are used for all sorts of emergencies and at football matches. When they are used to signal for help at sea, why do they not go out when they land in the water?

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Flares, they are used for all sorts of emergencies and at football matches. When they are used to signal for help at sea, why do they not go out when they land in the water?

If you burn a piece of combustible material, for example wood, and then you put it underwater, it stops burning essentially because you remove oxygen from around it; but if you burn something which has oxygen in itself, for example  an oxyhydrogen flame or a flare, it keeps burning; water shouldn't penetrate into the powder, however, or it will stop burn because that water will absorb heat and so switch off the flame.