JEE Main 12 Jan 2019 Evening Question 29
Question: In a radioactive decay chain, the initial nucleus is $ _90^{232}Th. $ At the end there are $ 6\alpha - $ particles and $ 4\beta - $ particles which are emitted. it the end nucleus is $ _Z^{A}X, $ A and Z are given by
[JEE Main Online Paper Held On 12-Jan-2019 Evening]
Options:
A) $ A=202;Z=80 $
B) $ A=200;Z=81 $
C) $ A=208;Z=80 $
D) $ A=208;Z=82 $
Show Answer
Answer:
Correct Answer: D
Solution:
- The mass number A of the end nucleus is $ 232-( 6\times 4 )=208 $
The atomic number Z of $ _Z^{A}X $ by conservation of charge is $ 90-( 6\times 2-4\times 1 )=82 $
