Reactivity of Metals with Oxygen

Introduction:
Metals can react with oxygen in the air to form metal oxides. The reactivity of metals towards oxygen varies, with some metals reacting vigorously and others reacting slowly or not at all. In this case, we need to identify which of the given metals reacts vigorously with oxygen.

Options:
a) Zinc
b) Magnesium
c) Sodium
d) Copper

Explanation:
To determine which metal reacts vigorously with oxygen, we need to consider the reactivity series of metals. The reactivity series is a list of metals arranged in order of their reactivity, with the most reactive metal at the top.

Reactivity Series:
- Potassium
- Sodium
- Calcium
- Magnesium
- Aluminum
- Zinc
- Iron
- Tin
- Lead
- Hydrogen
- Copper
- Silver
- Gold

Explanation of Options:
a) Zinc: Zinc is a moderately reactive metal. It reacts slowly with oxygen in the air to form zinc oxide. The reaction is not vigorous.
b) Magnesium: Magnesium is a highly reactive metal. It reacts vigorously with oxygen in the air to form magnesium oxide. The reaction is highly exothermic and produces a bright white light.
c) Sodium: Sodium is an extremely reactive metal. It reacts vigorously with oxygen in the air to form sodium oxide. The reaction is highly exothermic and can even result in a flame.
d) Copper: Copper is a relatively unreactive metal. It does not react with oxygen in the air at normal temperatures. It requires high temperatures or the presence of a catalyst to react with oxygen.

Conclusion:
Among the given options, sodium is the metal that reacts most vigorously with oxygen. It is an extremely reactive metal and can even catch fire when exposed to air. Magnesium also reacts vigorously with oxygen, but sodium is more reactive than magnesium.