Q 1 :    

Match List I with List II

  LIST I (Spectral Series for Hydrogen)   LIST II (Spectral Region/Higher Energy State)
A. Lyman I. Infrared region
B. Balmer II. UV region
C. Paschen III. Infrared region
D. Pfund IV. Visible region

 

Choose the correct answer from the options given below:               [2024]

  • A-I, B-III, C-II, D-IV

     

  • A-II, B-III, C-I, D-IV

     

  • A-II, B-IV, C-III, D-I

     

  • A-I, B-II, C-III, D-IV

     

(C)             For hydrogen atom,

                  (i) Lyman series lies in ultraviolet region.

                  (ii) First four lines of Balmer series are in visible region and higher ones are in ultraviolet region.

                  (iii) Paschen and Pfund series are in infrared region.

 



Q 2 :    

Number of spectral lines obtained in He+ spectra, when an electron makes transition from fifth excited state to first excited state will be _______ .             [2024]



(10)                 Fifth excited state means sixth shell and first excited state means second shell. Thus transition is from 6th to 2nd shell. Number of spectral lines when electrons make transition from n2 energy level to n1 energy level in a sample of gas atoms is:

                       (n2-n1)(n2-n1+1)2=(6-2)(6-2+1)2=10