Question

Element ${}_{26}^{108}Y$ is formed as a result of $3\beta$ and $2{\beta }^{-}$ decays. Find the parent element?

• A. ${}_{22}^{96}\Psi$
• B. ${}_{30}^{120}\iota$
• C. ${}_{24}^{120}\Omega$
• D. ${}_{14}^{18}\Delta {+}_{18}^{96}\vartheta$
• E. ${}_{28}^{120}\Pi$

Answer 1

The correct option is B ${}_{30}^{120}\iota$

Element ${}_{26}^{108}Y$ is formed as a result of $3\beta$ and $2{\beta }^{-}$ decay. Find the parent element.

Emission of 3 positive $\beta$ results in the following changes
Mass no. $\to$ No change

Atomic no. $\to$ decreases by 3 units

Emission of 2 negative $\beta$ results in the following changes:-

Mass no. $\to$No change
Atomic no. $\to$ increases by 2 units

Hence there is no net change in mass number.

Atomic no. decreases by 1 unit

Therefore Atomic no. of the parent is 1 greater than 26, i.e. 27.
The only option close to this is option (E) ${}_{28}^{120}II$