Copper is displaced from the solution of its salts by most metals because it

Correct answer: Is at the bottom of the activity series

Explanation: Metals higher in the reactivity (activity) series displace metals lower down from solutions of their salts. Copper is relatively unreactive and sits low in the series, so many common metals (e.g., Zn, Fe, Mg) can displace it from Cu²⁺ solutions.

• Is a transition element — Incorrect. Being a transition metal doesn’t determine whether it’s displaced.
• Is at the bottom of the activity series — Correct. Copper’s low reactivity means more reactive metals can displace it.
• Is very reactive — Incorrect. Copper is less reactive than most common metals.
• Has completely filled 3d-orbitals — Although Cu has a 3d¹⁰ configuration, this is not the reason for displacement in salt solutions.