Which one of the following has lowest enthalpy of atomization ?

Question

Accepted Answer

The question asks which element among the given options has the lowest enthalpy of atomization. The correct answer is Option 1: Zn (Zinc). Let's explore why this is the case and why the other options are incorrect.

### Explanation for Option 1: Zn

1. **Electronic Configuration**: Zinc has the electronic configuration [Ar] 3d¹⁰ 4s². The completely filled d-subshell (3d¹⁰) contributes to its stability, resulting in lower energy required to break the metallic bonds in the solid state.

2. **Metallic Bonding**: In zinc, the metallic bonding is relatively weaker compared to transition metals with partially filled d-orbitals. This is because the d-orbitals in zinc do not participate in bonding as effectively as in other transition metals, leading to lower enthalpy of atomization.

3. **Position in the Periodic Table**: Zinc is located at the end of the transition metal series, where the d-orbitals are fully filled. This results in weaker metallic bonding compared to elements with partially filled d-orbitals, which can form stronger metallic bonds due to more effective overlap.

### Explanation for Other Options

- **Option 2: Cu (Copper)**
  - Copper has the electronic configuration [Ar] 3d¹⁰ 4s¹. Despite having a filled d-subshell, copper exhibits stronger metallic bonding than zinc due to its ability to form a metallic lattice with more effective overlap of orbitals. This results in a higher enthalpy of atomization compared to zinc.

- **Option 3: Sc (Scandium)**
  - Scandium has the electronic configuration [Ar] 3d¹ 4s². As the first element in the transition series, scandium has partially filled d-orbitals, which contribute to stronger metallic bonding. This results in a higher enthalpy of atomization compared to zinc.

- **Option 4: Ni (Nickel)**
  - Nickel has the electronic configuration [Ar] 3d⁸ 4s². With partially filled d-orbitals, nickel forms strong metallic bonds due to effective d-orbital overlap. This leads to a higher enthalpy of atomization than zinc.

In conclusion, zinc has the lowest enthalpy of atomization among the given options due to its fully filled d-orbitals and weaker metallic bonding. This makes Option 1 the correct answer.