At a specific instant emission of radioactive compound is deflected in a magnetic field. The compound cannot emit

Options

A. electron
B. protons
C. `He^(2+)`
D. neutrons

Answer

To solve the problem, we need to analyze the behavior of different particles emitted by a radioactive compound when subjected to a magnetic field. The key point to remember is that only charged particles can be deflected in a magnetic field.

### Step-by-Step Solution:

1. **Understanding Radioactive Emission**:
Radioactive compounds can emit various types of particles, including alpha particles (helium nuclei), beta particles (electrons or positrons), and gamma rays (photons).

2. **Identifying Charged Particles**:
- Alpha particles (He²⁺) are positively charged.
- Beta particles (electrons, e⁻) are negatively charged.
- Both of these particles can be deflected in a magnetic field due to their charge.

3. **Identifying Neutral Particles**:
- Neutrons (n) are neutral particles and do not carry any charge.
- Since they lack charge, they cannot be deflected in a magnetic field.

4. **Conclusion**:
The question asks which type of emission cannot be deflected in a magnetic field. Since neutrons are neutral and do not experience a force in a magnetic field, they cannot be deflected.

5. **Final Answer**:
The radioactive compound cannot emit neutrons in a way that allows for deflection in a magnetic field. Therefore, the correct answer is option D: Neutrons.