A metal ion `M^(+2)` loses 3 electrons its oxidation number will be

Options

A. `-1`
B. 0
C. `+5`
D. `+3`

Answer

To determine the oxidation number of the metal ion \( M^{+2} \) after it loses 3 electrons, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Initial Oxidation State**:
The metal ion \( M^{+2} \) has an oxidation state of +2. This means it has lost 2 electrons compared to its neutral state.

**Hint**: Remember that the oxidation state indicates the total number of electrons lost or gained by an atom compared to its neutral form.

2. **Understand the Effect of Losing Electrons**:
When an atom loses electrons, its oxidation state increases. Each electron lost increases the oxidation state by +1.

**Hint**: Keep in mind that losing electrons (which are negatively charged) results in a higher positive charge.

3. **Calculate the Change in Oxidation State**:
Since the metal ion \( M^{+2} \) loses 3 electrons, we add 3 to the initial oxidation state of +2:
\[ \text{New Oxidation State} = +2 + 3 = +5 \]

**Hint**: When calculating the new oxidation state, simply add the number of electrons lost to the initial oxidation state.

4. **Conclusion**:
After losing 3 electrons, the oxidation state of the metal ion \( M \) is +5.

**Final Answer**: The oxidation number of the metal ion \( M \) after losing 3 electrons is +5.