General Knowledge - Physics - Discussion

Neutrons are a bi-product of fission. It's how Nuclear Reactors work and they are the essential element in a chain reaction, the control rods absorb emitted neutrons to prevent a runaway cascade. So Neutrons are emitted by radioactive elements - the phrasing of the question makes the answer all of the above.

Neutron is correct answer because in fission we get average 2.5 neutrons. And radioactivity is something else. As gamma rays are neutral similarly neutron.

But the difference is in their mass. A neutron is many time heavy than alpha beta and gamma so it can interact with matters and makes more effective results than gamma.

Neutrons are high-speed nuclear particles that have an exceptional ability to penetrate other materials. Of the five types of ionizing radiation discussed here, neutrons are the only one that can make objects radioactive. This process, called neutron activation, produces many of the radioactive sources that are used in medical, academic, and industrial applications (including oil exploration).

Because of their exceptional ability to penetrate other materials, neutrons can travel great distances in air and require very thick hydrogen-containing materials (such as concrete or water) to block them. Fortunately, however, neutron radiation primarily occurs inside a nuclear reactor, where many feet of water provide effective shielding.

Radioactive particles are:

Alpha particle - helium particle.
Beta particle- electron.
Gamma- electromagnetic radiation.

Alfa particle is 2 protons and 2 neutrons, thus having atomic no of 2 and mass no of 4. So, yes neutron is emitted.

All emitted from radioactive substance.

You -238 emitted 2 neutron.

As neutrons are neutrally charged particles they are not affected by any field applied to radioactive substance.

A radioactive atom emits an alpha particle or a beta particle and with each radiation it emits an electromagnetic wave known as a gamma wave. An alpha particle is an ionised He atom having a charge + 2, beta particle is an electron and gamma is an EM wave. So the only particle in the question which a radioactive atom cannot emit spontaneously is a neutron.

To put it more simply, Alpha rays emit +ve charge and beta rays emit -ve charge and lastly, gamma rays emit electromagnetic radiations. We may have studied neutrons in nuclear fission but it is platonically a by product and not the actual product.

Option D is correct because radioactivity is spontaneous emission.