The discovery of neutron became very late because

Options

A. neutrons are present in nucleus
B. neutrons are chargeless
C. neutrons are fundamental particles
D. all of the above.

Answer

**Step-by-Step Solution:**

1. **Understanding Neutrons**: Neutrons are subatomic particles found in the nucleus of an atom. They are one of the three main particles that make up an atom, the other two being protons and electrons.

2. **Charge of Neutrons**: Neutrons are unique because they do not carry any electric charge. This characteristic is crucial because charged particles (like protons and electrons) can be influenced by electric and magnetic fields.

3. **Impact of Charge on Discovery**: Since neutrons are chargeless, they do not exhibit deflection when subjected to electric or magnetic fields. This lack of interaction made it difficult for scientists to detect their presence using the methods available at the time of their discovery.

4. **Comparison with Other Particles**: In contrast, protons (positively charged) and electrons (negatively charged) can be easily detected and studied because they respond to electric and magnetic fields. This responsiveness allowed for earlier discoveries of these particles compared to neutrons.

5. **Conclusion**: The late discovery of neutrons can be attributed to their neutral charge and the resulting inability to detect them through the methods that were effective for charged particles. Therefore, the correct answer to the question is that the discovery of neutrons became very late because they are chargeless and do not show any deflection in electric or magnetic fields.

**Final Answer**: The discovery of neutrons became very late because they are chargeless, and they do not show any deflection in electric or magnetic fields.

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