What are the wavelengths of all infrared radiations coming out? — Atomic Structure Chemistry Question

💡 Solution & Explanation

Infrared radiations in the hydrogen spectrum for transitions ending at $n \ge 3$. From the $n=4$ state, the only available IR transition is $4 \to 3$ (Paschen series). Thus, there is only one IR wavelength, which corresponds to 1887.3 nm. Therefore, correct answer is B.