Q. No.Which of the following is correct match for hydrogen like species for the total energy of \(e^-\)?
| Species and Orbit | Energy (J/atom) | |
| 1. | \(3^{rd}\) orbit of \(Li^{2+}\) ion | \( -21.6 \times 10^{-19} \) |
| 2. | \(2^{nd}\) orbit of \(He^{+}\) ion | \( -10.8 \times 10^{-19}\) |
| 3. | \(2^{nd}\) orbit of \(Li^{2+}\) ion | \( -9.6 \times 10^{-19} \) |
| 4. | \(2^{nd}\) orbit of H-atom | \( -86.4 \times 10^{-19} \) |
Subtopic: Introduction of Atomic Structure | Hydrogen Spectra |
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Which of the spectral line of the H atom is suitable for heat treatment of muscular pain (involves radiation of wavelength of about 900 nm)?
(Given: \(\mathrm{R}_{\mathrm{H}}=10^5 \mathrm{~cm}^{-1}, \mathrm{~h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}, \mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}\))
1. Paschen series, ∞ → 3
2. Lyman series, ∞ → 1
3. Balmer series, ∞ → 2
4. Paschen series, 5 → 3
(Given: \(\mathrm{R}_{\mathrm{H}}=10^5 \mathrm{~cm}^{-1}, \mathrm{~h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}, \mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}\))
1. Paschen series, ∞ → 3
2. Lyman series, ∞ → 1
3. Balmer series, ∞ → 2
4. Paschen series, 5 → 3
Subtopic: Hydrogen Spectra |
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The shortest wavelength of the Paschen series for H-atom is:
| 1. | \(\dfrac{9}{R}\) | 2. | \(\dfrac{16}{R}\) |
| 3. | \(\dfrac{144}{7 R}\) | 4. | \(\dfrac{7 R}{144}\) |
Subtopic: Hydrogen Spectra |
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Calculate the velocity of the electron in the first orbit of H-atom.
(me= \(9.1\times10^{-31}\text{kg}\))
1. \(2.18 \times 10^5 \mathrm{~m} / \mathrm{s}\)
2. \(2.18 \times 10^6 \mathrm{~m} / \mathrm{s}\)
3. \(2.18 \times 10^7 \mathrm{~m} / \mathrm{s}\)
4. \(2.18 \times 10^4 \mathrm{~m} / \mathrm{s}\)
(me= \(9.1\times10^{-31}\text{kg}\))
1. \(2.18 \times 10^5 \mathrm{~m} / \mathrm{s}\)
2. \(2.18 \times 10^6 \mathrm{~m} / \mathrm{s}\)
3. \(2.18 \times 10^7 \mathrm{~m} / \mathrm{s}\)
4. \(2.18 \times 10^4 \mathrm{~m} / \mathrm{s}\)
Subtopic: Hydrogen Spectra |
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Find the radius of the 4th stationary orbit of an electron in a hydrogen atom, if the radius of the 3rd orbit is given as r .
| 1. | \(\dfrac{16r}{9}\) | 2. | \(\dfrac{6r}{16}\) |
| 3. | \(\dfrac{4r}{3}\) | 4. | \(\dfrac{3r}{4}\) |
Subtopic: Hydrogen Spectra |
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What is the minimum energy \((\text{in eV})\) required for an electron to excite from ground state to 1st excited state for hydrogen atom?
1. 10.5
2. 20.3
3. 50.2
4. 100
1. 10.5
2. 20.3
3. 50.2
4. 100
Subtopic: Hydrogen Spectra |
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How many spectral lines are obtained when an electron in \(\text{He}^+\) ion jumps from n=5 to n=1?
1. 10
2. 20
3. 70
4. 100
1. 10
2. 20
3. 70
4. 100
Subtopic: Hydrogen Spectra |
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Match the following:
1. A → (iv), B → (iii) C → (i), D → (ii)
2. A → (i), B → (iii) C → (ii), D → (iv)
3. A → (iv), B → (ii) C → (iii), D → (iv)
4. A → (i), B → (ii) C → (iii), D → (iv)
| (A) | Lyman | (i) | IR |
| (B) | Balmer | (ii) | IR |
| (C) | Paschen | (iii) | Visible |
| (D) | Pfund | (iv) | UV |
1. A → (iv), B → (iii) C → (i), D → (ii)
2. A → (i), B → (iii) C → (ii), D → (iv)
3. A → (iv), B → (ii) C → (iii), D → (iv)
4. A → (i), B → (ii) C → (iii), D → (iv)
Subtopic: Hydrogen Spectra |
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If the longest wavelength for the Paschen series in \(\text{H}-\)atom is \({\alpha\over 7\text{R}}\), the value of \(\alpha\) will be:
1. 144
2. 677
3. 890
4. 764
1. 144
2. 677
3. 890
4. 764
Subtopic: Hydrogen Spectra |
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The shortest wavelength in the Lyman series of H-atom is λ. and the longest wavelength in the Balmer series of He+ is \(\frac{x\lambda}5\).
The value of x is:
1. 7
2. 11
3. 13
4. 9
The value of x is:
1. 7
2. 11
3. 13
4. 9
Subtopic: Hydrogen Spectra |
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Level 2: 60%+
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