JEE Main 2022 · 26 Jun · Shift 1 · Physics Q48

PhysicsSingle correct+4 / -1Question 48 of 90

How many alpha and beta particles are emitted when Uranium $\mathrm{{}_{92}U^{238}}$ decays to lead $\mathrm{{}_{82}Pb^{206}}$ ?

3 alpha particles and 5 beta particles

6 alpha particles and 4 beta particles

4 alpha particles and 5 beta particles

8 alpha particles and 6 beta particles

Answer and worked solution

Official answer: D

Alpha particles. $\dfrac{238-206}4=8$ , which would lower Z by 16 (to 76).

Beta particles. Z must end at 82, so $82-76=6$ .

(D)

Topics:Radioactive decay

JEE Main 2022 · 26 Jun · Shift 1, Physics question 48