International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

Among the pairs listed, which metal is more reactive than iron?

1. Copper

2. Calcium

3. Zinc

4. Lead

The correct answer is: Calcium

Calcium is more reactive than iron because it is located higher in the reactivity series of metals. The reactivity series ranks metals based on their ability to displace other metals from compounds, react with acids, and undergo oxidation. Calcium is an alkali earth metal, which means it is highly reactive with water and acids. When looking at the reactivity series, calcium comes before iron, indicating that it can displace iron from its compounds. On the other hand, metals such as copper, zinc, and lead are less reactive compared to calcium. Copper, for example, is a much less reactive metal that does not react with water and can only displace metals below it in the series from their compounds. Zinc is more reactive than iron, but less so than calcium, and lead is relatively inactive compared to both calcium and iron.