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The rydberg formula, for the spectrum of...

The rydberg formula, for the spectrum of the hydorgen aotm where all terms have their usual menaning is

A

`hupsilon_(if)=(me^(4))/(8epsilon_0^(2)h^2)((1)/(n_f)-(1)/(n_i))`

B

`hupsilon_(if)=(me^(4))/(8epsilon_0^2h^2)((1)/n_(f)^2-(1)/(n_(i)^(2)))`

C

`hupsilon_(if)=(8epsilon_0^2h^2)/(me^(4))((1)/(n_f)-(1)/(n_(i)))`

D

`hupsilon_(if)=(8epsilon_0^2h^2)/(me^(4))((1)/n_(f)^(2)-(1)/(n_(i)^(2)))`

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The correct Answer is:
To derive the Rydberg formula for the spectrum of the hydrogen atom, we will follow these steps: ### Step 1: Understand the Energy Levels The energy of an electron in the nth orbit of a hydrogen atom is given by the formula: \[ E_n = -\frac{M e^4}{8 \epsilon_0^2 h^2 n^2} \] where: - \( E_n \) is the energy of the electron in the nth orbit, - \( M \) is the mass of the electron, - \( e \) is the charge of the electron, - \( \epsilon_0 \) is the permittivity of free space, - \( h \) is Planck's constant, - \( n \) is the principal quantum number. ### Step 2: Calculate the Energy Difference When an electron transitions from an initial energy level \( n_i \) to a final energy level \( n_f \), the change in energy (\( \Delta E \)) can be calculated as: \[ \Delta E = E_{n_f} - E_{n_i} \] Substituting the energy levels: \[ \Delta E = \left(-\frac{M e^4}{8 \epsilon_0^2 h^2 n_f^2}\right) - \left(-\frac{M e^4}{8 \epsilon_0^2 h^2 n_i^2}\right) \] This simplifies to: \[ \Delta E = \frac{M e^4}{8 \epsilon_0^2 h^2} \left(\frac{1}{n_i^2} - \frac{1}{n_f^2}\right) \] ### Step 3: Relate Energy to Frequency According to Planck's relation, the energy of a photon emitted or absorbed during this transition is also given by: \[ \Delta E = h \nu \] where \( \nu \) is the frequency of the emitted or absorbed radiation. ### Step 4: Combine the Equations Equating the two expressions for \( \Delta E \): \[ h \nu = \frac{M e^4}{8 \epsilon_0^2 h^2} \left(\frac{1}{n_i^2} - \frac{1}{n_f^2}\right) \] From this, we can express the frequency \( \nu \): \[ \nu = \frac{M e^4}{8 \epsilon_0^2 h^3} \left(\frac{1}{n_i^2} - \frac{1}{n_f^2}\right) \] ### Step 5: Write the Rydberg Formula The Rydberg formula for the wavelengths of the spectral lines can be derived from the frequency: \[ \frac{1}{\lambda} = R \left(\frac{1}{n_f^2} - \frac{1}{n_i^2}\right) \] where \( R \) is the Rydberg constant given by: \[ R = \frac{M e^4}{8 \epsilon_0^2 h^3} \] ### Final Result Thus, the Rydberg formula for the spectrum of the hydrogen atom is: \[ \frac{1}{\lambda} = R \left(\frac{1}{n_f^2} - \frac{1}{n_i^2}\right) \] ---

To derive the Rydberg formula for the spectrum of the hydrogen atom, we will follow these steps: ### Step 1: Understand the Energy Levels The energy of an electron in the nth orbit of a hydrogen atom is given by the formula: \[ E_n = -\frac{M e^4}{8 \epsilon_0^2 h^2 n^2} \] where: ...
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NCERT FINGERTIPS ENGLISH-ATOMS -Assertion And Reason
  1. The rydberg formula, for the spectrum of the hydorgen aotm where all t...

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  2. (A) atoms of each element are stable and emit characteristic spectrum....

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  3. (A) atom as a whole is electrically neutral. (R)atom contains equal ...

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  4. (A) according to classical electromagnetic theory an accelerated parti...

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  5. (A) in alpha particle scattering number of alpha paritcle undergoing h...

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  6. (A) most of the mass of the atom is concentrated in its nucleus. (R)...

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  7. (A) the trajetory traced by an incident particle depends on the impact...

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  8. (A) in the experiment of alpha particle scattering, extremely thin gol...

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  9. (A) the total energy of an electron revolving in any stationary orbit ...

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  10. Statement -1 : Large angle scattering of alpha particles led to the di...

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  11. Assertion: For the scattering of alpha-particles at a large angles, on...

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  12. Assertion: Hydrogen atom consists of anly one electron but its emissio...

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  13. (A) bohr model can not be extended to two or more electron atoms. (R...

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  14. Assertion: Bohr had to postulate that the electrons in stationary orbi...

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  15. (A) bohr's third postulaate states that the stationary orbits are thos...

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  16. Assertion: Electrons in the atom are held due to coulomb forces. Rea...

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