A  ${\mathrm{He}}^{+}$ ion is in its first excited state. Its ionization energy is?
 

Important Questions on Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom

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12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 30

In ${\mathrm{Li}}^{++}$, an electron in the first Bohr orbit is excited to a level by radiation of wavelength $\lambda$. when the ion gets de-excited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of $\lambda$ ?
(Given :$\mathrm{h}=6.63\times {10}^{34} \mathrm{J} \mathrm{s}; \mathrm{c}=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$)

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12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 31

In a Frank-Hertz experiment, an electron of energy $5.6 eV$ passes through mercury vapour and emerges with an energy $0.7 eV$. The minimum wavelength of photons emitted by mercury atoms is close to:

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IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 32

A hydrogen atom, initially in the ground state is excited by absorbing a photon of wavelength $980 \stackrel{\mathrm{o}}{A}$. The radius of the atom in the excited state, in terms of Bohr radius $a_0$, will be: $\left(hc=12500 eV-\stackrel{\mathrm{o}}{A}\right)$

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12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 33

Consider an electron in a hydrogen atom revolving in its second excited state (having radius $4.65 \stackrel{\mathrm{o}}{A}$). The de-Broglie wavelength of this element is:

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IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 34

Taking the wavelength of first Balmer line in hydrogen spectrum ($n=3$ to $n=2$) as $660 \mathrm{nm}$, the wavelength of the $2$nd Balmer line ($n=4$ to $n=2$) will be:

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12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 35

The electron in a hydrogen atom first jumps from the third excited state to the second excited state and subsequently to the first excited state. The ratio of the respective wavelength, $\frac{{\lambda }_1}{{\lambda }_2}$, of the photons emitted in this process is:

HARD

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IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 36

An excited $H{e}^{++}$ ion emits two photons in succession, with wavelengths $108.5 \mathrm{nm}$ to $30.4 \mathrm{nm}$, in making a transition to ground state. The quantum number $n$, corresponding to its initial excited state is: (for photon of wavelength $\lambda$, energy $E=\frac{1240 \mathrm{eV}}{\lambda (\mathrm{in} \mathrm{nm})}$)

HARD

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IMPORTANT

ISC Physics Class 12, Part-2>Chapter 13 - Atom, Origin of Spectra : Bohr's Theory of Hydrogen Atom>For DIFFERENT COMPETITIVE EXAMINATIONS>Q 37

Radiation coming from transitions $n=2$ to $n=1$ of hydrogen atoms fall on $H{e}^{++}$ ions in $n=1$ to $n=2$ states. The possible transition of helium ions as they absorb energy from the radiation is: