Question

An unstable nucleus which starts a decay process is called the _____.

Answer 1

It Is Called The Parent Nuclide

Answer 2

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:

$_{11}^{22}\textrm{Na}\rightarrow _{10}^{22}\textrm{Ne}+_{+1}^0\beta$

Here, $_{11}^{22}\textrm{Na}$ is a parent nuclide and $_{10}^{22}\textrm{Ne}$ 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 $t_{1/2}$

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.