Electronic configuration of divalent cation of Eu is 

Options

A. `4f^(6)`
B. `4f^(7)`
C. `5f^(7)`
D. `5f^(8)`

Answer

To determine the electronic configuration of the divalent cation of Europium (Eu), we will follow these steps:

### Step 1: Identify the Atomic Number of Europium
Europium (Eu) has an atomic number of 63. This means that in its neutral state, it has 63 electrons.

### Step 2: Write the Ground State Electronic Configuration
The ground state electronic configuration of Europium can be derived by filling the orbitals according to the Aufbau principle. The configuration is:
- 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 4f⁷ 6s²

This can be simplified using the nearest noble gas, Xenon (Xe), which has an atomic number of 54. Thus, the electronic configuration can be written as:
- [Xe] 4f⁷ 6s²

### Step 3: Determine the Configuration of the Divalent Cation (Eu²⁺)
A divalent cation means that Europium has lost two electrons. In the case of lanthanides like Europium, the electrons are typically lost from the outermost s orbital first. Therefore, we remove the two electrons from the 6s orbital:
- [Xe] 4f⁷ 6s² → [Xe] 4f⁷ 6s⁰

Thus, the electronic configuration of the divalent cation (Eu²⁺) becomes:
- [Xe] 4f⁷

### Final Answer:
The electronic configuration of the divalent cation of Europium (Eu²⁺) is:
- [Xe] 4f⁷

---