In a radioactive series
\( ^{235} _{92}L \to ^{235} _{92}M \to ^{231} _{90}N \to ^{231} _{91}\phi \)
The particles emitted are respectively
A
\( \beta , \beta , \alpha \)
B
\( \alpha , \gamma , \beta \)
C
\( \gamma , \alpha , \beta \)
D
\( \alpha , \alpha , \beta \)
E
\( \beta , \alpha , \beta \)
Verified Correct Answer: C.
Physical Principles & Numerical Solution
From L → M ⇒ No change in both mass and atomic number, meaning a gamma ray was released
From M → L ⇒ Change in both mass and atomic number, meaning an alpha particle was released
From L → \(\phi\) Change in atomic number only, meaning a beta particle was released
Source: Myschool Past Questions Archive (Record #41569)