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Q. No.In Rutherford's alpha-particle scattering experiment, only a few alpha particles rebound back because
Choose the correct answer from the option given below:
1. \(\mathrm{A, B}\) Only
2. \(\mathrm{B, E}\) Only
3. \(\mathrm{C, D}\) Only
4. \(\mathrm{A, C,E}\) Only
| \(\mathrm{A}.\) | The size of gold nucleus is very small as compared to the size of gold atom. |
| \(\mathrm{B}.\) | Alpha particle and gold nucleus have equal charge. |
| \(\mathrm{C}.\) | The impact parameter is minimum for a few alpha particles. |
| \(\mathrm{D}.\) | A few alpha particles have very high kinetic energy. |
| \(\mathrm{E}.\) | Only a few alpha particles undergo head-on collision with the nuclei. |
1. \(\mathrm{A, B}\) Only
2. \(\mathrm{B, E}\) Only
3. \(\mathrm{C, D}\) Only
4. \(\mathrm{A, C,E}\) Only
Subtopic: Various Atomic Models |
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Using Bohr's model, calculate the ratio of the magnetic field generate due to the motion of the electrons in the \(2^{nd}\) and \(4^{th}\) orbits of hydrogen atom.
1. \(1:1\)
2. \(32:2\)
3. \(16:3\)
4. \(32:1\)
1. \(1:1\)
2. \(32:2\)
3. \(16:3\)
4. \(32:1\)
Subtopic: Bohr's Model of Atom |
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Level 2: 60%+
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The ratio of momentum of the photons of the \(1^\text{st}\) and \(2^\text{nd}\) line of Balmer series of Hydrogen atoms is \(\alpha / \beta .\) The possible values of \(\alpha\) and \(\beta\) are:
1. \(27~\text{and}~20\)
2. \(3~\text{and}~16\)
3. \(5~\text{and}~36\)
4. \(20~\text{and}~27\)
1. \(27~\text{and}~20\)
2. \(3~\text{and}~16\)
3. \(5~\text{and}~36\)
4. \(20~\text{and}~27\)
Subtopic: Bohr's Model of Atom |
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Angular momentum of an electron in a hydrogen atoms is \(\dfrac{3 {h}}{\pi}\), then the energy electron is: (in eV)
1. \(-1.51\)
2. \(-0.85\)
3. \(-0.38\)
4. \(-0.28\)
1. \(-1.51\)
2. \(-0.85\)
3. \(-0.38\)
4. \(-0.28\)
Subtopic: Bohr's Model of Atom |
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In the hydrogen atom, the electron makes a transition from the higher orbit \((i)\) to a lower orbit \((f)\). The ratio of the radius of the orbits in given by \(r_i: r_f=16: 4 .\)
The wavelength of photon emitted due to this transition is: (in nm)
(Given Rydberg constant = \(\left.1.0973 \times 10^7 / \text{m}\right)\)
1. \(121\)
2. \(242\)
3. \(486\)
4. \(974\)
The wavelength of photon emitted due to this transition is: (in nm)
(Given Rydberg constant = \(\left.1.0973 \times 10^7 / \text{m}\right)\)
1. \(121\)
2. \(242\)
3. \(486\)
4. \(974\)
Subtopic: Spectral Series |
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An alpha particle with a kinetic energy of \(7.7~\text{MeV}\) approaches a gold nucleus head-on. Assuming the nucleus remains stationary. The distance of closest approach of the alpha particle is:
Given: Atomic number of gold, \( (Z=79);\) charge of an alpha particle, \((q_\alpha=+2e);\) elementary charge, \((e=1.6\times10^{-19},\text{C});\) and \(({1}/{4\pi\varepsilon_0}=9\times10^9,\text{N m}^2\text{C}^{-2}).\)
1. \(2.95 \times 10^{-14}\) m
2. \(2.95 \times 10^{-16}\) m
3. \(3.85 \times 10^{-16}\) m
4. \(3.85 \times 10^{-14}\) m
Subtopic: Various Atomic Models |
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The energy of an electron in an orbit of the Bohr’s atom is \(-0.04 {E}_0 ~\text{eV}\) where \(E_0\) is the ground state energy. If \(L\) is the angular momentum of the electron in this orbit and \(h\) is the Planck’s constant, then \(\dfrac{2 \pi {L}}{h}\) is:
1. \(2\)
2. \(4\)
3. \(5\)
4. \(6\)
1. \(2\)
2. \(4\)
3. \(5\)
4. \(6\)
Subtopic: Bohr's Model of Atom |
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\(7.9 ~\text {MeV}\) \(\alpha\)-particle scatters from a target material of atomic number \(79.\) From the given data the estimated diameter of nuclei of the target material is (approximately):
\(\left[\frac{1}{4 \pi \epsilon_{o}}=9 \times 10^9 ~\text{Nm}^2 / \text{C}^2 \text { and electron charge }=1.6 \times 10^{-19} \text{C}\right]\)
1. \(5.76\times10^{-14}\) m
2. \(1.44\times10^{-13}\) m
3. \(2.88\times10^{-14}\) m
4. \(1.69\times10^{-12}\) m
\(\left[\frac{1}{4 \pi \epsilon_{o}}=9 \times 10^9 ~\text{Nm}^2 / \text{C}^2 \text { and electron charge }=1.6 \times 10^{-19} \text{C}\right]\)
1. \(5.76\times10^{-14}\) m
2. \(1.44\times10^{-13}\) m
3. \(2.88\times10^{-14}\) m
4. \(1.69\times10^{-12}\) m
Subtopic: Various Atomic Models |
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The smallest wavelength of the Lyman series is \(91~\text{nm}\). The difference between the largest wavelength of the Paschen and Balmer series is nearly:
1. \(1875\) mm
2. \(1550\) mm
3. \(1217\) mm
4. \(1784\) mm
1. \(1875\) mm
2. \(1550\) mm
3. \(1217\) mm
4. \(1784\) mm
Subtopic: Spectral Series |
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In hydrogen atom spectrum, (\(R\rightarrow\) Rydberg's constant)
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1. \(\mathrm{B,D}\) Only
2. \(\mathrm{A,B~\text{and}~C}\) Only
3. \(\mathrm{A,B~\text{and}~D}\) Only
4. \(\mathrm{A,B}\) Only
| \(\mathrm{A}\). | The maximum wavelength of the radiation of Lyman series is \(\dfrac{4}{3 R}\) |
| \(\mathrm{B}\). | The Balmer series lies in the visible region of the spectrum |
| \(\mathrm{C}\). | The minimum wavelength of the radiation of Paschen series is \(\dfrac{9}{{R}}\). |
| \(\mathrm{D}\). | The minimum wavelength of Lyman series is \(\dfrac{5}{{4R}}\) |
1. \(\mathrm{B,D}\) Only
2. \(\mathrm{A,B~\text{and}~C}\) Only
3. \(\mathrm{A,B~\text{and}~D}\) Only
4. \(\mathrm{A,B}\) Only
Subtopic: Spectral Series |
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