Burning Magnesium

Most recent answer: 10/22/2007

why does magnesium burn so hard, fast and hot ?
- mathew (age 15)
Great question Mathew -

Atoms have a positive nucleus with just enough negative electrons "roaming " around it to just balance the charge. Oxygens in the air have a strong affinity for extra electrons and magnesium atoms can readily give up electrons. The reaction gives Mg2+ ions and O2- ions which are strongly attracted to each other to form MgO, thus giving off lots of energy.

(published on 10/22/2007)

Follow-Up #1: Water on a magnesium fire? Bad advice

Why can't you use water or a fire extinguisher to extinguish a magnesium fire?
- shannon (age 15)
San Antonio, TX, USA
It's because magnesium eats water for breakfast and makes the fire stronger.
Seriously, there is a reaction Mg (s) + 2H2O --> Mg(OH)2 + H2 that produces hydrogen gas.  This hydrogen then burns by combining with oxygen in the air and makes the fire hotter.


(published on 11/15/2009)