Which one of the following nuclear transformation is (n,p) type ?

Options

A. `Li_3^7 + H_1^1 to Be_4^7 + n_0^1`
B. `As_33^75 + He_2^4 to Br_35^78 +n_0^1`
C. `Bi_83^209 + H_1^2 to Po_84^210 +n_0^1`
D. `Sc_21^45 +n_0^1 to Ca_20^45 + H_1^1`

Answer

To determine which nuclear transformation is of the (n,p) type, we need to understand what this type of reaction entails. In an (n,p) type nuclear reaction, a neutron is bombarded onto a nucleus, resulting in the emission of a proton.

### Step-by-Step Solution:

1. **Understand the (n,p) Reaction**:
- In an (n,p) reaction, a neutron (represented as \( ^1_0n \)) is absorbed by a nucleus, and a proton (represented as \( ^1_1p \)) is emitted from that nucleus.

2. **Analyze the Given Options**:
- We have four nuclear transformations to analyze.

3. **Option 1: \( ^7_3Li + ^1_1H \)**:
- In this reaction, a proton is bombarded on Lithium-7. Since we are looking for a neutron bombardment, this option does not fit the (n,p) type.

4. **Option 2: Alpha Particle Reaction**:
- This option involves an alpha particle and does not involve a neutron bombardment. Therefore, it cannot be classified as an (n,p) reaction.

5. **Option 3: \( ^{209}_{83}Bi + ^2_1H \)**:
- Here, bismuth-209 is acted upon by deuterium (which contains a neutron). However, this option results in the emission of a neutron instead of a proton, so it does not qualify as an (n,p) reaction.

6. **Option 4: \( ^{A}_{Z}X + ^1_0n \rightarrow ^{A-1}_{Z-1}Y + ^1_1p \)**:
- This option correctly shows a neutron being bombarded onto a nucleus, resulting in the emission of a proton. This fits the definition of an (n,p) type nuclear transformation.

7. **Conclusion**:
- The correct answer is **Option 4**, as it represents a nuclear transformation where a neutron is bombarded and a proton is emitted.