What are the oxidation states of phosphorous in the following :
`PO_(4)^-3`

Answer

To determine the oxidation state of phosphorus in the phosphate ion, \( PO_4^{3-} \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Ion and Its Charge**:
The ion we are considering is \( PO_4^{3-} \). The overall charge of the ion is -3.

2. **Know the Oxidation State of Oxygen**:
The common oxidation state of oxygen is -2. In the phosphate ion, there are 4 oxygen atoms.

3. **Calculate the Total Contribution of Oxygen**:
Since there are 4 oxygen atoms, the total contribution to the charge from oxygen is:
\[ 4 \times (-2) = -8 \]

4. **Set Up the Equation for the Oxidation State of Phosphorus**:
Let the oxidation state of phosphorus be \( x \). The equation based on the total charge of the ion can be set up as follows:
\[ x + (-8) = -3 \]

5. **Solve for the Oxidation State of Phosphorus**:
Rearranging the equation gives:
\[ x - 8 = -3 \]
\[ x = -3 + 8 \]
\[ x = +5 \]

6. **Conclusion**:
The oxidation state of phosphorus in the phosphate ion \( PO_4^{3-} \) is +5.

### Final Answer:
The oxidation state of phosphorus in \( PO_4^{3-} \) is +5.