Due to lanthanoid contraction which of the following properties is not expected to be similar in the sme vertical columns of second and third row transition elements ?

Options

A. Atomic radii
B. Ionisation elergies
C. Magnetic moments
D. Lattice energies

Explanation

To solve the question regarding the effects of lanthanoid contraction on properties of second and third row transition elements, we can break down the solution into several steps:

### Step-by-Step Solution:

1. **Understanding Lanthanoid Contraction**:
- Lanthanoid contraction refers to the gradual decrease in the size of the lanthanide ions as we move from La (Lanthanum) to Lu (Lutetium) in the periodic table. This contraction affects the size of the elements in the subsequent periods.

2. **Impact on Atomic Size**:
- Due to lanthanoid contraction, the atomic size of the second and third row transition elements in the same vertical column (group) becomes more similar. This means that properties dependent on atomic size will also be similar.

3. **Identifying Properties Affected by Atomic Size**:
- Properties such as atomic radius, ionization energy, and lattice energy are influenced by atomic size. Therefore, these properties are expected to be similar for the second and third row transition elements in the same group.

4. **Identifying Properties Not Affected by Atomic Size**:
- Magnetic moment is a property that depends on the number of unpaired electrons in an atom. The number of unpaired electrons is determined by the electronic configuration of the element, which does not directly depend on atomic size.

5. **Conclusion**:
- Since magnetic moment is influenced by the electronic configuration and not by atomic size, it is the property that is not expected to be similar in the same vertical columns of second and third row transition elements due to lanthanoid contraction.

### Final Answer:
The property that is not expected to be similar in the same vertical columns of second and third row transition elements due to lanthanoid contraction is **magnetic moment**.