Early workers mistakenly thought neutron beams wereradiation. Why? What evidence led to the correct conclusion?

These are neutral and massless. Gamma rays interact least with matter and, thus, penetrate most. A block of lead several inches thick is needed to stop them. Therefore, an external gamma ray source is the most dangerous because the energy can ionize many layers of living tissue.

A more variable case occurs with emission of neutrons, which are neutral and massive. Outside a nucleus, neutrons decay with a half-life of 10.6 min into a proton and an electron (and an antineutrino). With energies ranging from very low to very high, they may be scattered or captured by interaction with nuclei.

Neutron beams and gamma radiation have no charge, we cannot observe deflection using electric and magnetic fields. Neutron beams have a neutron that has a mass almost equal to the mass of proton. This makes neutron beams different from gamma radiation.

Scientists have found that neutron beams could induce the emission of protons from a substance while gamma rays do not produce emission.

Because they both have no charge, neutron beams are mistaken for gamma rays. Neutron beams, however, have mass. The fact that neutron methods can cause proton emission of substances, whereas gamma rays cannot, led to their correct identification.