When subatomic particles undergo reaction energy is conserved, but mass is not necessarily conserved. However, a particle's mass 'contributes' to its total energy, in accordance with Einstein'f famouns equation, `E= mc^(2)`
In this question, `E` denotes the equivalent energy when a particle of mass `m` is converted into energy. The particle can also have additional energy due to its motion and its interactions with other particles.
Consider a neutron at rest, and well separated from other particles. It decays into a proton, an electron, and an undetected third particle: `"Neutron"rarr"proton"+"electron"+"third particle"`
The table below summarizes some data from a single nuetron decay. Column `2` shows the rest mass of the particle times the speed of light squared.
`{:("Particle",Mx C^(2),,"Kinetic Energy",),(,(MeV),,(MeV),),("Neutron",940.97,,0,),("Proton",939.66,,0.02,),("Electron",0.51,,0.42,):}`
Could this reaction occur ?
`"Proton"rarr"neutron"+"other particles"`

Options

A. Yes, if the other particles have much more kinetic energy than mass energy
B. Yes, but only if the proton has potential energy (due to interactions with other particles)
C. No, because a neutron is more massive than a proton
D. No, because a proton is positively charged while a neutron is electrically neutral

Answer

B

Explanation

A proton with only mass-energy can never decay into a neutron as the mass of neutro is more than that of the proton. However, If the proton has some additional energy in the form of PE such that its energy is more than rest mass-energy of the neutron, it can decay into neutron and release some energy.