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Why does magnesium burn with an intense white light?

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magnesium processing Vapor-deposited magnesium crystals produced from magnesium processing.

Magnesium burns with an intense white light because it is a strongly reactive metal that undergoes a rapid oxidation-reduction reaction when exposed to oxygen at high temperatures.12

Specifically, when magnesium is heated above 645 °C (1,190 °F) in dry air, it reacts vigorously to form magnesium oxide (MgO). During this process, each magnesium atom transfers two electrons to an oxygen atom. This chemical reaction releases a significant amount of energy in the form of intense heat and bright white light.123

Because of this property, finely divided magnesium has historically been utilized in photographic flash powders and continues to be used in various pyrotechnic and explosive devices.13