Magnesium
Formula: Mg — Magnesium
Appearance: Silvery-white lustrous metal; ribbon or strip form
Hazard: Fire hazard when burning · Cannot be extinguished with water or CO₂
Properties
One of the lightest structural metals. Density 1.74 g/cm³, melting point 650°C. Burns with an intensely bright white flame producing MgO (white powder) and Mg₃N₂. Very reactive: dissolves rapidly in dilute acids with vigorous hydrogen evolution; reacts slowly with hot water. Available as ribbon for easy ignition and controlled burning.
Historical Context
Magnesium was isolated by Humphry Davy in 1808 by electrolysis of magnesium oxide. Its brilliant combustion made it the original photographic flash material — magnesium flash powder was used from the 1860s until replaced by electronic flash bulbs in the 1920s. Magnesium is the eighth most abundant element in Earth’s crust and is essential for all living organisms (the central atom of chlorophyll is magnesium).
Experiments
Burning Ribbon: Ignite a 3–5 cm piece of magnesium ribbon outdoors with a lighter — brilliant white flame producing white MgO ash. Do not look directly at the flame (produces UV). One of the most dramatic demonstrations of a reactive metal burning in air.
Acid Reaction: Drop a small piece of magnesium ribbon into dilute hydrochloric acid — vigorous hydrogen evolution, much faster than zinc or iron, and the tube warms noticeably from the exothermic reaction.
Experiments using this chemical:
(No specific experiments listed yet — see demonstrations above)
Safety
Fire hazard. Burning magnesium cannot be extinguished with water (produces flammable H₂), CO₂ (magnesium reacts with it), or standard dry powder. Use dry sand to smother. Do not look directly at the flame — produces intense UV radiation. Adult supervision required. Only burn small pieces (≤5 cm) outdoors or under a fume hood.
Keep away from moisture and sources of ignition during storage.