Materials such as lithium and finely divided magnesium are reactive with what?

Materials such as lithium and finely divided magnesium are reactive with what?

• A. Oxygen
• B. Nitrogen
• C. Carbon dioxide
• D. Water

Answer: (D)

These materials are known to react with water. When lithium or finely divided magnesium comes into contact with water, they react, releasing hydrogen gas and forming a metal hydroxide (the reaction is exothermic and can be vigorous). That hydrogen release creates a real fire or explosion hazard, which is why water is the key reactant discussed for these metals. They don’t illustrate the same rapid, hydrogen-producing reaction with nitrogen or carbon dioxide under normal conditions, and while some metals can burn in oxygen, the notable hazard highlighted here is their reaction with water.

These materials are known to react with water. When lithium or finely divided magnesium comes into contact with water, they react, releasing hydrogen gas and forming a metal hydroxide (the reaction is exothermic and can be vigorous). That hydrogen release creates a real fire or explosion hazard, which is why water is the key reactant discussed for these metals. They don’t illustrate the same rapid, hydrogen-producing reaction with nitrogen or carbon dioxide under normal conditions, and while some metals can burn in oxygen, the notable hazard highlighted here is their reaction with water.