Which of the following metals can be used as a reducing agent?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Calcium
A reducing agent removes oxygen from another substance (or gives it electrons) and is itself oxidised. Highly reactive metals such as sodium, calcium and aluminium do this readily, so they are used to reduce the oxides of less reactive metals; calcium is one of them.
Why the other options are incorrect
Option (2) Silver — Incorrect. Silver is a very unreactive metal and does not easily give up electrons.
Option (3) Tungsten — Incorrect. Tungsten is a hard, high-melting, fairly unreactive metal used for bulb filaments.
Option (4) Gold — Incorrect. Gold is a noble metal, among the least reactive of all.