In neutron capture by an atomic nucleus, the mass number of the nucleus changes by
A) −2.
B) −1.
C) 0.
D) +1.
E) +2.

Question

Quizplus · Accepted Answer

In neutron capture, a neutron is absorbed by the atomic nucleus and a proton and an electron neutrino are released. This means that the atomic number increases by 1 (since a proton is added) and the mass number remains the same (since the electron neutrino has negligible mass). Therefore, the correct answer is +1.

In Neutron Capture by an Atomic Nucleus, the Mass Number