Question

During a negative beta decay, a neutron in the nucleus decays emitting an electron.

• A. An atomic electron is ejected
• B. An electron which is already present within the nucleus is ejected

Answer 1

The correct option is A An atomic electron is ejected

In a beta minus decay process, a neutron inside the nucleus converts into a proton and an electron, and an antineutrino is created.
${}_6^{14}C{\to }_7^{14}N+e^{-}+\overline{v}$
In the above example, a neutron was converted into a proton, thus the mass number wasn't altered. But the atomic number was increased by one.
Also, an electron and an antineutrino were created and emitted from the nucleus.