Answer: The correct answer is parent nuclide.
Explanation:
From the given options:
Option 1: Parent nuclide
This term is defined as the nuclide which decays into specific daughter nuclide when a radioactive decay takes place. This nuclide decays because it is unstable in nature.
Option 2: Daughter nuclide
This term is defined as the nuclide which is formed when a parent nuclide decays during a radioactive decay process.
For Example: Decay of Sodium-22 to Neon -22 by beta-plus decay. The equation follows:
[tex]_{11}^{22}\textrm{Na}\rightarrow _{10}^{22}\textrm{Ne}+_{+1}^0\beta[/tex]
Here, [tex]_{11}^{22}\textrm{Na}[/tex] is a parent nuclide and [tex]_{10}^{22}\textrm{Ne}[/tex] is a daughter nuclide.
Option 3: Half life
This term is defined as the time taken by the isotope to decompose to half of its original value. It is represented by [tex]t_{1/2}[/tex]
Option 4: Mass defect
This term is defined as the difference between the mass of an isotope and its mass number. This represents binding energy.
Hence, from the above information, the correct answer is parent nuclide.
