In reactivity series which one is most reactive:

Question

Accepted Answer

The correct option is (2):

Magnesium (Mg) is the most reactive among the given elements because of its position in the reactivity series. The reactivity series is a list of metals arranged in decreasing order of their reactivity, which essentially reflects their tendency to lose electrons and form positive ions. Metals higher up in the series are more reactive because they lose electrons more readily. Magnesium is an alkaline earth metal, and it is located higher in the reactivity series than zinc, lead, and copper. This means magnesium has a stronger tendency to donate its valence electrons and participate in chemical reactions, often reacting vigorously with acids, water (especially steam or hot water), and oxygen.

The incorrect option is (1): Zn
Zinc (Zn) is less reactive than magnesium. While zinc is quite reactive and can displace hydrogen from acids and react with steam, it is positioned below magnesium in the reactivity series, indicating a lesser tendency to lose electrons compared to magnesium.

The incorrect option is (3): Pb
Lead (Pb) is significantly less reactive than both magnesium and zinc. It is positioned much lower in the reactivity series, meaning it has a lower tendency to lose electrons and is less prone to oxidation. Lead reacts only slowly with acids and is generally unreactive with water.

The incorrect option is (4): Cu
Copper (Cu) is one of the least reactive metals among the choices provided. It is located very low in the reactivity series, below hydrogen, which means it does not react with dilute acids to produce hydrogen gas and is also unreactive with water or steam under normal conditions. Copper's low reactivity is why it is often found uncombined in nature.