Question

After the decay of a single \( \beta^- \) particle, the parent and daughter nuclei are?

• A. isotopes
• B. isos
• C. isomers
• D. isotone

Hint:

In \( \beta^- \) decay, the neutron converts into a proton, increasing the atomic number by 1 while keeping the mass number unchanged. This results in the parent and daughter nuclei being isos.

Answer 1

The Correct Option is B

Step 1: Understanding Beta Decay

Beta-minus (\( \beta^- \)) decay occurs when a neutron in the nucleus is converted into a proton while emitting an electron (\( \beta^- \) particle) and an antineutrino (\( \bar{\nu} \)):

\[ n \rightarrow p + e^- + \bar{\nu} \]

This results in the atomic number (\( Z \)) of the nucleus increasing by 1, while the mass number (\( A \)) remains unchanged.

Step 2: Definition of Isobars

• Isotopes: Nuclei with the same atomic number (\( Z \)) but different mass numbers (\( A \)).
• Isobars: Nuclei with the same mass number (\( A \)) but different atomic numbers (\( Z \)).
• Isomers: Nuclei with the same atomic and mass numbers but different energy states.
• Isotones: Nuclei with the same number of neutrons but different atomic numbers.

Since the mass number remains the same during \( \beta^- \) decay but the atomic number changes, the parent and daughter nuclei are isobars.