# Physics Class 12 NCERT Solutions: Chapter 12 Atoms Part 2 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Q: 6. A hydrogen atom initially in the ground level absorbs a photon, which excites it to the level. Determine the wavelength and frequency of the photon.

For ground level,

Let be the energy of this level. It is known that is related with as:

The atom is excited to a higher level, .

Let be the energy of this level.

The amount of energy absorbed by the photon is given as:

For a photon of wavelength , the expression of energy is written as:

Where,

And, frequency of a photon is given by the relation,

Hence, the wavelength of the photon is 97 nm while the frequency is .

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