Q94 / 160 · JIPMER 2013 · Physics
A radioactive element ${ }_{90} X^{238}$ decays into ${ }_{83} Y^{222}$. The number of $\beta$-particles emitted are
- Correct answerA1
- B2
- C4
- D6
Solution
$\alpha$-particles are emitted $=\frac{238-222}{4}=4$
The atomic number is decreased
$90-4 \times 2=82$
As atomic number of ${ }_{83} Y^{222}$, So, atomic number is increased by 1 , therefore, one $\beta$-particle is emitted.
Hence, the correct answer is option: 'A'.