Question

A hydrogen atom initially in the ground level absorbs a photon and is excited n = 4 level then the frequency of photon is ?

• A. $3.1 \times 10^{15}\text{ Hz}$
• B. $3.1 \times 10^{18}\text{ Hz}$
• C. $9.1 \times 10^{15}\text{ Hz}$
• D. $9.1 \times 10^{18}\text{ Hz}$

Answer 1

Answer: (A)

$3.1 \times 10^{15}\text{ Hz}$

Answer 2

Since $\upsilon = \frac{c}{\lambda}$

Here $c = 3 \times 10^{8}ms^{- 1}$

$\lambda = 9.7 \times 10^{- 8}m$

$\therefore\upsilon = \frac{3. \times 10^{8}}{9.7 \times 10 -^{8}} = 3.1 \times 10^{15}Hz$