AP EAMCET Engineering 18 Sep 2020 Shift 2 Paper

According to question,
Initial nuclei =‌92238U
Final nuclei =‌82206Pb
Change in atomic number =92−82=10
When an α - particle emits from a nuclei, then its atomic number is decreased by 2 units and atomic mass is decreased by 4 units. When a β -particle emits from a nuclei, then atomic number of parent nuclei is increased by 1 unit whereas its atomic mass remains same.
Change in atomic mass =238−206=32
Since, atomic mass changes only due to emission α -particle, hence number of emitted α -particle
=‌

32

4

=8
Number of emitted β -particles = total change in atomic number due to emission of α -particles total change in atomic number
=8×2−10=6