The ratio of the frequency corresponding to the third line in Lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of Li2+ spectrum is

Question

The ratio of the frequency corresponding to the third line in Lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of Li2+ spectrum is (A) (4/5) (B) (5/4) (C) (4/3) (D) (3/4)

Tardigrade Admin · Accepted Answer

For Lyman series, n1=1 and for third line, n2=4 barv1 =R H Z2((1/n12)-(1/n22)) =R H (1)2((1/1)-(1/16))=(15/16) R H (∵ For H atom Z=1) For Balmer series, n1=2 and for first line, n2=3 barv2 =R H Z2((1/(2)2)-(1/(3)2)) [ text For Li 2+, Z=3] =R H (3)2((1/4)-(1/9))=9 R H ((5/36)) (v1/v2) =(15 R H × 36/16 × 9 × 5 R H )=(3/4)

Q. The ratio of the frequency corresponding to the third line in Lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of Li²⁺ spectrum is

$\frac{4}{5}$

$\frac{5}{4}$

$\frac{4}{3}$

$\frac{3}{4}$

$\frac{3}{8}$

Q. The ratio of the frequency corresponding to the third line in Lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of Li2+ spectrum is

54​

45​

34​

43​