A photon of hard gamma radiations knocks out a proton for `._(12)^(24)Mg` nucleaus to from:

Options

A. The isotope of parent nucleus
B. The isobar of parent nucleus
C. The nuclide `._(11)^(23)Na`
D. The iosbar of `._(11)^(23)Na`

Answer

To solve the problem, we need to analyze the effect of a photon of hard gamma radiation knocking out a proton from the magnesium nucleus.

### Step-by-Step Solution:

1. **Identify the Initial Nucleus**:
The nucleus in question is magnesium, represented as \( _{12}^{24}\text{Mg} \). Here, 12 is the atomic number (number of protons) and 24 is the mass number (total number of protons and neutrons).

2. **Understand the Effect of the Photon**:
A photon of hard gamma radiation can provide enough energy to knock out a proton from the nucleus. When a proton is knocked out, the atomic number decreases by 1, and the mass number also decreases by 1.

3. **Calculate the New Atomic Number and Mass Number**:
- **New Atomic Number**:
\[ 12 - 1 = 11 \]
- **New Mass Number**:
\[ 24 - 1 = 23 \]

4. **Identify the New Element**:
The new nucleus formed after knocking out a proton will have an atomic number of 11 and a mass number of 23. The element with atomic number 11 is sodium (Na).

5. **Conclusion**:
Therefore, the nucleus formed after the photon knocks out a proton from magnesium \( _{12}^{24}\text{Mg} \) is \( _{11}^{23}\text{Na} \).

### Final Answer:
The correct answer is sodium, represented as \( _{11}^{23}\text{Na} \).