Assertion : `Cu^(2+)` ion is a coloured ion .
Reason : Every ion with unpaired electron is coloured .

Options

A. If assertion and reason are TRUE and reason is the correct explanation of STATEMENT-1
B. If assertion and reason are TRUE but reason is NOT the correct explanation of STATEMENT-1
C. If assertion is TRUE and reason is FALSE
D. If assertion is FALSE and reason is TRUE

Answer

### Step-by-Step Text Solution:

1. **Understanding the Assertion**: The assertion states that the `Cu^(2+)` ion is a colored ion. To determine if this is true, we need to analyze the electronic configuration of the copper ion.

2. **Electronic Configuration of Copper**: The ground state electronic configuration of a neutral copper atom (Cu) is:
\[ \text{Cu: } [\text{Ar}] 3d^{10} 4s^1 \]
When copper loses two electrons to form the `Cu^(2+)` ion, it loses the one electron from the 4s orbital and one from the 3d orbital.

3. **Electronic Configuration of `Cu^(2+)`**: The electronic configuration of `Cu^(2+)` becomes:
\[ \text{Cu}^{2+}: [\text{Ar}] 3d^9 \]
This indicates that there are 9 electrons in the 3d subshell.

4. **Distribution of Electrons in 3d Orbitals**: The 3d subshell can hold a maximum of 10 electrons. According to Hund's rule, we fill the orbitals singly before pairing. The distribution of the 9 electrons in the 3d orbitals will be as follows:
- 5 orbitals (3d) will each get 1 electron first (total 5 electrons).
- Then, we will start pairing the electrons. The next 4 will fill as follows:
- 6th electron pairs with one of the first five,
- 7th pairs with another,
- 8th pairs with another,
- 9th remains unpaired.

Thus, there is **1 unpaired electron** in the `Cu^(2+)` ion.

5. **Conclusion on Color**: The presence of unpaired electrons in the `Cu^(2+)` ion indicates that it is a paramagnetic species, which is typically colored. Therefore, the assertion that `Cu^(2+)` is a colored ion is **true**.

6. **Analyzing the Reason**: The reason states that every ion with unpaired electrons is colored. This statement is **not entirely accurate**. While unpaired electrons can lead to color, it is specifically the d or f block elements that exhibit this property due to their ability to absorb visible light. Therefore, the reason is **false**.

7. **Final Answer**: The assertion is true, but the reason is false. The correct answer is that the assertion is correct and the reason is incorrect.