Concept:Beta minus (\(\beta^{-}\)) decay occurs when a neutron-rich nucleus transforms a neutron into a proton, emitting an electron and an antineutrino in the process.
Formula:$$ _{0}^{1}\text{n} \rightarrow _{1}^{1}\text{p} + _{-1}^{0}\text{e} + \bar{\nu}_e $$
Solution:- Electrons do not inherently "exist" inside the nucleus. They are created at the exact moment of decay.
- The weak nuclear force mediates the transformation of a neutron into a proton, generating a high-speed electron (the beta particle) that is immediately ejected.
Why other options are incorrect:Option A describes ionization, not nuclear radioactivity. Option C is a common misconception; nuclei contain protons and neutrons, not pre-existing electrons. Option D describes gamma rays.
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