A nuclide emits a beta-particle (e) in the process, that atomic number
Answer Details
When a nuclide emits a beta-particle (e), a neutron inside the nucleus is converted into a proton and an electron is emitted. The mass number of the nuclide remains constant because the total number of protons and neutrons in the nucleus remains the same. However, since a neutron is converted into a proton, the atomic number of the nuclide increases by 1, because the atomic number of an element is equal to the number of protons in its nucleus. Therefore, the correct option is: "the atomic number increases by 1 while the mass number remains constant".