Can lanthanum ion (Z = 57) exist in +4 oxidation state ? Justify your answer.

Explanation

To determine whether the lanthanum ion (Z = 57) can exist in a +4 oxidation state, we will analyze its electronic configuration and the implications of losing electrons.

### Step 1: Identify the Electronic Configuration of Lanthanum
The atomic number of lanthanum (La) is 57. The nearest noble gas configuration is that of xenon (Xe), which has an atomic number of 54. The electronic configuration of lanthanum can be written as:
\[ \text{[Xe]} 5d^1 6s^2 \]

### Step 2: Determine the Possible Oxidation States
Lanthanum has two electrons in the 6s subshell and one electron in the 5d subshell. The possible oxidation states can be derived from the loss of these electrons:
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