Question

Arrange the following in the order of increasing wavelength
(A) Lyman
(B) Balmer
(C) Paschen
(D) Brackett
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D).
• B. (D), (C), (B), (A).
• C. (B), (A), (D), (C).
• D. (C), (B), (D), (A).

Hint:

Series order: Lyman (UV), Balmer (Visible), Paschen and Brackett (Infrared), with increasing wavelength.

Answer 1

The Correct Option is B

Step 1: Identify Hydrogen Spectral Series Regions
- Lyman series: Ultraviolet (shortest wavelength, highest energy).
- Balmer series: Visible spectrum.
- Paschen series: Infrared region.
- Brackett series: Infrared (longer wavelength than Paschen).
Step 2: Determine Wavelength Order
Increasing wavelength is associated with decreasing energy levels in electron transitions. Longer wavelengths indicate transitions from lower energy levels.
Step 3: Final Ordering
Therefore, the series in order of increasing wavelength is: \[ \text{Lyman}<\text{Balmer}<\text{Paschen}<\text{Brackett} \]
Final Answer: \[ \boxed{\text{(D), (C), (B), (A)}} \]