AP EAMCET201822 Apr 2018Evening ShiftChemistryStructure of AtomActual
The ratio of lowest energy in terms of wave numbers of Balmer and Lyman series of lines of atomic spectrum of hydrogen is
Options
- A5 : 27
- B27 : 5
- C20 : 27
- D27 : 2
Correct answer
A. 5 : 27
Step-by-step solution
(a) Wave number (v)=R Z^2 1 n_ L ^2 - 1 n_ H ^2 Wave number for lowest energy for Balmer series (n_ L =2, n_ H =3 ) v=R [ 1 4 - 1 9 ]= 5 36 R Wave number for lowest energy for Lyman series: (n_ L =1, n_ H =2 ) v=R [1- 1 4 ]= 3 4 R Thus, ratio of Balmer/Lyman is = R .5 / 36 R .3 / 4 = 5 4 3 36 = 5 27 Hence ratio =5: 27