Q.

List-I shows various functional dependencies of energy (E) on the atomic number (Z). Energies associated with certain phenomena are given in List-II. Choose the option that describes the correct match between the entries in List-I to those in List-II.               [2025]

  List-I   List-II
(P) E∝Z2 (1) Energy of characteristic X-rays
(Q) E∝(Z-1)2 (2) Electrostatic part of the nuclear binding energy for stable nuclei with mass numbers in the range 30 to 170
(R) E∝(Z-1) (3) Energy of continuous X-rays
(S) E is practically independent of Z (4) Average nuclear binding energy per nucleon for stable nuclei with mass number in the range 30 to 170
    (5) Energy of radiation due to electronic transitions from hydrogen-like atoms

 

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

Ans.

(3)

(P)  Energy of H-like atom  E=-13.6Z2n2

         ∴  E∝Z2    (P)→(5)

(Q)  Energy of characteristic X-ray by Moseley's correction

         E=-13.6(Z-1)2[1n12-1n22]

         or,  E∝(Z-1)2    (Q)→(1)

(R)  Electrostatic binding energy∝Z(Z-1)

          (R)→(2)

(S)  For stable nuclei with mass number in the range 30 to 170, binding energy per nucleon is constant and the graph is a straight line.

         ∴  (S)→(4)