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Hydrogen atom absorbs radiations of wave...

Hydrogen atom absorbs radiations of wavelength `lambda_0` and consequently emit radiations of 6 different wavelengths, of which two wavelengths are longer than `lambda_0`. Chosses the correct alternative(s).

A

The final excited staate of the atoms is n=4

B

The initial state of the atoms is n =2

C

The initial state of the atoms is n =3

D

There ae three transitions belonging to Lyman series

Text Solution

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The correct Answer is:
To solve the problem, we need to analyze the transitions of an electron in a hydrogen atom when it absorbs radiation of wavelength \( \lambda_0 \) and subsequently emits radiation of 6 different wavelengths, with 2 of those wavelengths being longer than \( \lambda_0 \). ### Step-by-Step Solution: 1. **Understanding the Absorption and Emission Process**: - When a hydrogen atom absorbs a photon of wavelength \( \lambda_0 \), the electron transitions from a lower energy level to a higher energy level. This higher energy level will be denoted as \( n \). 2. **Determining the Number of Emission Wavelengths**: - The problem states that the atom emits 6 different wavelengths. The number of possible transitions (or wavelengths) from an energy level \( n \) is given by the formula \( \frac{n(n-1)}{2} \). - Setting this equal to 6, we have: \[ \frac{n(n-1)}{2} = 6 \] Multiplying both sides by 2 gives: \[ n(n-1) = 12 \] - Solving the quadratic equation \( n^2 - n - 12 = 0 \), we find that \( n = 4 \) (the positive solution). 3. **Identifying the Energy Levels**: - The possible energy levels for the transitions are \( n = 1, 2, 3, 4 \). The electron can transition from \( n = 4 \) to lower energy levels \( n = 3, 2, 1 \). 4. **Determining Wavelengths Longer than \( \lambda_0 \)**: - The energy difference between two levels is inversely proportional to the wavelength of the emitted radiation. Therefore, transitions with smaller energy differences will correspond to longer wavelengths. - The transitions from \( n = 4 \) to \( n = 3 \) and from \( n = 3 \) to \( n = 2 \) will have smaller energy differences compared to transitions from \( n = 4 \) to \( n = 1 \) or \( n = 2 \) to \( n = 1 \). 5. **Identifying Valid Transitions**: - The transitions that yield wavelengths longer than \( \lambda_0 \) are: - \( n = 4 \) to \( n = 3 \) (longer wavelength) - \( n = 3 \) to \( n = 2 \) (longer wavelength) - The other transitions (from \( n = 4 \) to \( n = 1 \), \( n = 3 \) to \( n = 1 \), and \( n = 2 \) to \( n = 1 \)) will produce shorter wavelengths. 6. **Conclusion**: - The final excited state of the atom is \( n = 4 \). - The initial excited state could be \( n = 2 \) since it can also produce longer wavelengths. - There are three transitions in the Lyman series (from \( n = 2 \) to \( n = 1 \), \( n = 3 \) to \( n = 1 \), and \( n = 4 \) to \( n = 1 \)). ### Final Answer: The correct alternatives are: - The final excited state of the atom is \( n = 4 \). - The initial excited state of the atom may be \( n = 2 \). - There are three transitions in the Lyman series.

To solve the problem, we need to analyze the transitions of an electron in a hydrogen atom when it absorbs radiation of wavelength \( \lambda_0 \) and subsequently emits radiation of 6 different wavelengths, with 2 of those wavelengths being longer than \( \lambda_0 \). ### Step-by-Step Solution: 1. **Understanding the Absorption and Emission Process**: - When a hydrogen atom absorbs a photon of wavelength \( \lambda_0 \), the electron transitions from a lower energy level to a higher energy level. This higher energy level will be denoted as \( n \). 2. **Determining the Number of Emission Wavelengths**: ...
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