Q.

List-I shows different radioactive decay processes and List-II provides possible emitted particles. Match each entry in List-I with an appropriate entry from List-II, and choose the correct option.                            [2023]

  List-I   List-II
(P) U92238→Pa91234 (1) one α particle and one β+ particle
(Q) Pb82214→Pb82210 (2) three β- particles and one α particle
(R) Tl81210→Pb82206 (3) two β- particles and one α particle
(S) Pa91228→Ra88224 (4) one α particle and one β- particle
    (5) one α particle and two β+ particles

 

1 P → 4, Q → 3, R → 2, S → 1  
2 P → 4, Q → 1, R → 2, S → 5  
3 P → 5, Q → 3, R → 1, S → 4  
4 P → 5, Q → 1, R → 3, S → 2  

Ans.

(1)

In α-decay, mass number (A) decreases by 4 units and atomic number (Z) decreases by 2 units.

In β- decay, A does not change but Z increases by 1 unit.

In β+ decay, A does not change but Z decreases by 1 unit.

(P)   U23892→Pa23491

        N1=238-2344=1→1α

        N2-N3=(92-91)-42=-1→1β-

        ∴  1α and 1β- emission.

(Q)   Pb21482→Pb21082

         N1=214-2104=1→1α

        N2-N3=(82-82)-42=-2→2β-

         ∴ 1α and 2β- emission.

(R)    Tl21081→Pb20682

         N1=210-2064=1→1α

         N2-N3=(81-82)-42=-3→3β-

          ∴  1α and 3β- emission.

(S)     Pa22891→Ra22488

          N1=228-2244=1→1α

          N2-N3=(91-88)-42=1→1β+

          ∴  1α and 1β+ emission.