Question

Which of the following series in H-spectra occurs in IR region?

• A. Lyman
• B. Pashen
• C. Bracket
• D. Balmer

Answer 1

Answer: (B), (C)

The correct options are
B Pashen
C Bracket

The lines in lyman series are obtained in UV region when electrons return to first energy level from higher energy levels 2, 3, 4, 5, 6.
The lines in balmer series are obtained in visible region when electrons return to second energy level from higher energy levels 3, 4, 5, 6.
The lines in paschen series are obtained in near infrared region when electrons return to third energy level from higher energy levels 4, 5, 6.
The lines in Brackett series are obtained in mid infrared region when electrons return to second energy level from higher energy levels 5, 6, 7.
The lines in pfund series are obtained in far infrared region when electrons return to second energy level from higher energy levels 6, 7.
So, the series of lines in H-spectra occurs in IR region are Paschen and Brackett.