Reactivity series determines steam reaction and carbon reduction extraction

Steps:

• Identify metals that react with steam: those above hydrogen in reactivity series, like zinc (Zn + H₂O → ZnO + H₂).
• Recall extraction methods: moderately reactive metals (e.g., zinc, iron) use carbon reduction; highly reactive ones (e.g., magnesium, calcium) require electrolysis.
• Compare options: magnesium and calcium are too reactive for carbon reduction; copper is too unreactive for steam reaction.
• Select zinc: satisfies both criteria.

Why D is correct:

• Zinc reacts with steam (Zn + H₂O → ZnO + H₂) and its ore (ZnO) reduces with carbon (ZnO + C → Zn + CO), per reactivity series.

Why the others are wrong:

• A. Magnesium: extracted by electrolysis, not carbon; reacts with cold water, not typically steam.
• B. Calcium: extracted by electrolysis; too reactive for carbon reduction.
• C. Copper: does not react with steam; extracted by partial roasting and self-reduction.

Final answer: D