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161. Following results are observed when sodium metal is irradiated with different wavelengths. Calculate: (a) threshold wavelength and (b) Planck’s constant.
λ(nm) 500 450 400
v x 10^-5(cm s^-1) 2.55 4.35 5.35

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Short Answer Type

162.

How does Bohr's model explain the stability of an atom?

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Long Answer Type

163.

How does Bohr's model of atom explain the atomic spectra of hydrogen and hydrogenlike particles?

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Short Answer Type

164. What is the maximum number of emission lines when the excited electron of a H atom in n = 6 drops to the ground state?

Number of lines produced when electron from nth shell drops to the ground state

There 15 lines are produced because of the following transition:

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165. The electron energy in hydrogen atom is given by E_n = (-2.18 x 10^-18)/n² J. Calculate the energy required to remove an electron completely from the n=2 orbit. What is the longest wavelength of light in cm that can be used to cause this transition?

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166. How will you account for the simultaneous appearance of large number of lines in the hydrogen spectrum?

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Long Answer Type

167.

Derive the expressions:
$left parenthesis straight i right parenthesis space increment straight E space equals space 2.18 space cross times space 10 to the power of negative 18 end exponent straight J space open square brackets fraction numerator 1 over denominator straight n subscript 1 superscript 2 end fraction minus space fraction numerator 1 over denominator straight n subscript 2 superscript 2 end fraction close square brackets left parenthesis ii right parenthesis space straight v with bar on top space equals 109677 space open square brackets fraction numerator 1 over denominator straight n subscript 1 superscript 2 end fraction minus fraction numerator 1 over denominator straight n subscript 2 superscript 2 end fraction close square brackets cm to the power of negative 1 end exponent$

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168.

What are frequency and wavelength of a photon emitted during a transition from n=5 state to n = 2 state in hydrogen atom?

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169.

What is the wavelength of ligh emitted when the election in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n = 2?

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170.

What is the energy in joules, required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is - 2.18 X 10^-11 ergs

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