Question

Choose the correct ascending order of ionization energy for Zn, Cu, Ag:

• A. Ag<Cu<Zn
• B. Zn<Cu<Ag
• C. Cu<Zn<Ag
• D. Zn<Ag<Cu

Hint:

Ionization energy increases across a period and decreases down a group, but transition metals show exceptions due to electron configuration.

Answer 1

The Correct Option is A

Step 1: Understanding ionization energies.
Ionization energy generally increases across a period from left to right and decreases down a group. Zinc (Zn), Copper (Cu), and Silver (Ag) are transition metals, but their ionization energies vary due to the electron configuration and relativistic effects.
Step 2: Explanation of the order.
- Ag (silver) has a relatively low ionization energy because of the relativistic contraction and the stability of its electron configuration.
- Cu (copper) has a higher ionization energy than Ag but lower than Zn due to its filled \( 3d^{10} \) subshell.
- Zn (zinc) has the highest ionization energy because its electron configuration is \( 3d^{10} 4s^2 \), which is stable and less likely to lose electrons.
Step 3: Conclusion.
Therefore, the correct ascending order of ionization energies is: \[ \text{Ag}<\text{Cu}<\text{Zn} \] which corresponds to option (A).