An element X decays, first by positron emission and then two \[\alpha \]-particles are emitted in successive radioactive decay. If the product nuclei has a mass number 229 and atomic number 89, the mass number and atomic number of element X are -
A)237, 93
B)237, 94
C)221, 84
D)237, 92
Correct Answer:
B
Solution :
Given \[A-8=224.\] \[Z-5=89\] \[\Rightarrow A=237,Z=94.\]