The Reaction of Metals with Oxygen

Sodium readily reacts with oxygen in the air, forming sodium oxide. A freshly cut surface of sodium initially appears shiny but quickly dulls due to this reaction. Sodium is stored under oil to prevent exposure to oxygen and water.

Magnesium reacts with oxygen when heated, producing a very bright light and forming a white powdery substance called magnesium oxide. This reaction is not as fast as sodium's reaction with oxygen.

When aluminum is heated in a Bunsen burner flame, it melts and develops a dull coating of aluminum oxide, which is an ionic compound and not shiny.

Zinc, a shiny gray metal, also melts when heated in a Bunsen burner flame. While it reacts with oxygen, the immediate visible change isn't as pronounced as with magnesium.

An iron nail simply glows red when heated. However, increasing the surface area of iron by using iron filings or steel wool significantly increases its reaction rate with oxygen, leading to sparking and burning, especially in an oxygen-enriched environment.