Question

In hydrogen atom, which one of the following transitions produce a spectrum line of maximum wavelength?

• A. 6 to 5
• B. 5 to 2
• C. 4 to 1
• D. 2 to 1

Answer 1

Answer: (A)

6 to 5

Answer 2

For hydrogen atom spectrum,
$\frac{1}{\lambda} =R \left(\frac{1}{n_{f}^{2}} -\frac{1}{n_{i}^{2}}\right)$
Therefore, for ${6 \, to\, 5; \lambda = \frac{30}{R}}$
for ${5 \, to\, 2; \lambda = \frac{10}{3R}}$
for ${4 \, to\, 1; \lambda = \frac{16}{15R}}$
for ${2 \, to\, 1; \lambda = \frac{4}{3R}}$
Hence, wavelength is maximum for transition 6 to 5.