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The ratio of the frequency corresponding to the third line in the lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of `Li^(2+)` spectrum isA. `4/5`B. `5/4`C. `4/3`D. `3/4` |
Answer» Correct Answer - D Lyman series , `n_1=1` For third line of Lyman series , `n_2=4` For hydrogen , Z=1 `upsilon_H=c/lambda=c. R_H Z^2 (1/n_1^2 -1/n_2^2)` `=c.R_H (1)^2 (1/1 -1/(4)^2) =15/16 R_H .c` For lithium , Z =3 For first line of balmer series , `n_1=2 , n_2 =3` `upsilon_(Li^(2+)) =c.R_H(1)^2 (1/1-1/(4)^2)=15/16R_H . c` For lithium, Z=3 For First line of balmer series , `n_1=2, n_2=3` `upsilon_(Li^(2+))=c. R_H (3)^2 (1/(2)^2 -1/(3)^2)=c. R_Hxx9xx5/36` `=5/4c. R_H` `upsilon_H/upsilon_(Li^(2+)) =((15//16)cR_H)/((5//4)cR_H)=15/16xx4/5=3/4` |
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