Which of the following statements is not correct according to Rutherford model?
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M.C.Q (1 Marks)
228 Q→02Assertion (A) & Reason (B) MCQ
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15 Q→042 Marks Questions
51 Q→053 Marks Question
47 Q→064 Marks Questions
11 Q→075 Marks Questions
35 Q→Sample Questions
Atoms questions
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Find the true statement.
What is the purpose of filament in electron gun inside a cathode ray tube?
An element has number of proton = 7. Then what will be its atomic number?
The radius of the shortest orbit in a one-electron system is $18\ pm.$ It may be
View full solution →For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
Reason (R): The different elements have different spectra.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is NOT the correct explanation of A.
- A is true, but R is false.
- A is false and R is also false.
Reason (R): The different elements have different spectra.
For question two statements are given$-$one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion $(A):$ The positively charged nucleus of an atom has a radius of almost $10^{-15}m.$
Reason $(R):$ In $\alpha-$particle scattering experiment, the distance of closest approach for $\alpha-$particles is $10^{-15}m.$
Assertion $(A):$ The positively charged nucleus of an atom has a radius of almost $10^{-15}m.$
Reason $(R):$ In $\alpha-$particle scattering experiment, the distance of closest approach for $\alpha-$particles is $10^{-15}m.$
- ✓Both $A$ and $R$ are true, and $R$ is the correct explanation of $A.$
- BBoth $A$ and $R$ are true, but $R$ is $\text{NOT}$ the correct explanation of $A.$
- C$A$ is true, but $R$ is false.
- D$A$ is false and $R$ is also false.
Answer: A.
View full solution →For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
Reason (R): The band spectrum consists of coloured bands of light on a dark background.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is NOT the correct explanation of A.
- A is true, but R is false.
- A is false and R is also false.
Reason (R): The band spectrum consists of coloured bands of light on a dark background.
For question two statements are given$-$one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below.
Assertion $(A):$ A tube light emits white light
Reason $(R):$ Emission of light in a tube takes place at a very high temperature.
Assertion $(A):$ A tube light emits white light
Reason $(R):$ Emission of light in a tube takes place at a very high temperature.
- ABoth $A$ and $R$ are true, and $R$ is the correct explanation of $A.$
- BBoth $A$ and $R$ are true, but $R$ is $NOT$ the correct explanation of $A.$
- C$A$ is true, but $R$ is false.
- ✓$A$ is false and $R$ is also false.
Answer: D.
View full solution →For question two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
Reason (R): Energy is a scalar quantity. It can have positive or negative value.
- Both A and R are true, and R is the correct explanation of A.
- Both A and R are true, but R is NOT the correct explanation of A.
- A is true, but R is false.
- A is false and R is also false.
Reason (R): Energy is a scalar quantity. It can have positive or negative value.
Choose the correct alternative from the clues given at the end of the each statement:
In the ground state of .......... electrons are in stable equilibrium, while in .......... electrons always experience a net force. (Thomson’s model/ Rutherford’s model.)
In the ground state of .......... electrons are in stable equilibrium, while in .......... electrons always experience a net force. (Thomson’s model/ Rutherford’s model.)
Answer the following questions, which help you understand the difference between Thomson’s model and Rutherford’s model better.Keeping other factors fixed, it is found experimentally that for small thickness t, the number of α-particles scattered at moderate angles is proportional to t. What clue does this linear dependence on t provide?
Choose the correct alternative from the clues given at the end of the each statement:
An atom has a nearly continuous mass distribution in a .......... but has a highly non-uniform mass distribution in .......... (Thomson’s model/ Rutherford’s model.)
An atom has a nearly continuous mass distribution in a .......... but has a highly non-uniform mass distribution in .......... (Thomson’s model/ Rutherford’s model.)
Answer the following questions, which help you understand the difference between Thomson’s model and Rutherford’s model better.
Is the average angle of deflection of α-particles by a thin gold foil predicted by Thomson’s model much less, about the same, or much greater than that predicted by Rutherford’s model?
Is the average angle of deflection of α-particles by a thin gold foil predicted by Thomson’s model much less, about the same, or much greater than that predicted by Rutherford’s model?
Answer the following questions, which help you understand the difference between Thomson’s model and Rutherford’s model better.
In which model is it completely wrong to ignore multiple scattering for the calculation of average angle of scattering of α-particles by a thin foil?
In which model is it completely wrong to ignore multiple scattering for the calculation of average angle of scattering of α-particles by a thin foil?
Define the distance of closest approach. An α-particle of kinetic energy 'K' is bombarded on a thin gold foil. The distance of the closest approach is 'r'. What will be the distance of closest approach for an α-particle of double the kinetic energy?
The ground state energy of hydrogen atom is –13.6 eV. What are the kinetic and potential energies of the electron in this state?
The radius of the innermost electron orbit of a hydrogen atom is $5.3\times 10^{–11} m.$ What are the radii of the $n = 2$ and $n = 3$ orbits?
View full solution →If Bohr’s quantisation postulate (angular momentum $=\text{nh}/\pi$) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why then do we never speak of quantisation of orbits of planets around the sun?
View full solution →Suppose you are given a chance to repeat the alpha-particle scattering experiment using a thin sheet of solid hydrogen in place of the gold foil. $($Hydrogen is a solid at temperatures below $14 K.)$ What results do you expect?
View full solution →Obtain the first Bohr’s radius and the ground state energy of a muonic hydrogen atom $[$i.e., an atom in which a negatively charged muon $(\mu)$ of mass about $207m_e$ orbits around a proton$].$
View full solution →A difference of $2.3\ eV$ separates two energy levels in an atom. What is the frequency of radiation emitted when the atom make a transition from the upper level to the lower level?
View full solution →In accordance with the Bohr’s model, find the quantum number that characterises the earth’s revolution around the sun in an orbit of radius $1.5 \times 10^{11}$ m with orbital speed $3 \times 10^4 m/s. ($Mass of earth $= 6.0 \times 1024 \ kg.)$
View full solution →What is the shortest wavelength present in the Paschen series of spectral lines?
The total energy of an electron in the first excited state of the hydrogen atom is about –3.4 eV.
- What is the kinetic energy of the electron in this state?
- What is the potential energy of the electron in this state?
- Which of the answers above would change if the choice of the zero of potential energy is changed?
When the electron orbiting in hydrogen atom in its ground state moves to the third excited state, show how the de Broglie wavelength associated with it would be affected.
- The figure shows the plot of binding energy (BE) per nucleon as a function of mass number A. The letters A, B, C, D and E represent the positions of typical nuclei on the curve. Point out, giving reasons, the two processes (in terms of A, B, C, D and E), one of which can occur due to nuclear fission and the other due to nuclear fusion.
- Identify the nature of the radioactive radiations emitted in each step of the decay process given below.
In $1911,$ Rutherford, along with his assistants, $H$.
Geiger and $E$. Marsden, performed the alpha particle scattering experiment. $H$.
Geiger and $E$. Marsden took radioactive source $(^{214}_{83}\text{Bi})$ for $\alpha- $ particles.
A collimated beam of $\alpha-$ particles of energy $5.5 MeV$ was allowed to fall on $2.1 \times 10^{-7} m$ thick gold foil. The $\alpha-$ particles were observed through a rotatable detector consisting of a Zinc sulphide screen and microscope. It was found that $CL-$ particles got scattered. These scattered $\alpha-$ particles produced scintillations on the zinc sulphide screen. Observations of this experiment are as follows?
Most of the $\alpha-$ particles passed through the foil without deflection.
Only about $0.14\%$ of the incident $\alpha-$ particles scattered by more than $1^\circ$
Only about one $\alpha-$ particle in every $8000 \ \alpha-$ particles deflected by more than $90^\circ$
These observations led to many arguments and conclusions which laid down the structure of the nuclear model of an atom.
View full solution →Geiger and $E$. Marsden, performed the alpha particle scattering experiment. $H$.
Geiger and $E$. Marsden took radioactive source $(^{214}_{83}\text{Bi})$ for $\alpha- $ particles.
A collimated beam of $\alpha-$ particles of energy $5.5 MeV$ was allowed to fall on $2.1 \times 10^{-7} m$ thick gold foil. The $\alpha-$ particles were observed through a rotatable detector consisting of a Zinc sulphide screen and microscope. It was found that $CL-$ particles got scattered. These scattered $\alpha-$ particles produced scintillations on the zinc sulphide screen. Observations of this experiment are as follows?
Most of the $\alpha-$ particles passed through the foil without deflection.
Only about $0.14\%$ of the incident $\alpha-$ particles scattered by more than $1^\circ$
Only about one $\alpha-$ particle in every $8000 \ \alpha-$ particles deflected by more than $90^\circ$
These observations led to many arguments and conclusions which laid down the structure of the nuclear model of an atom.
- Rutherford's atomic model can be visualised as.
- Gold foil used in Geiger $-$ Marsden experiment is about $10^{-8}m$ thick. This ensures.
- Gold foil's gravitational pull is small or possible.
- Gold foil is deflected when $\alpha-$ particle stream is not incident centrally over it.
- Gold foil provides no resistance to passage of $\alpha-$ particles.
- Most $\alpha-$ particle will not suffer more than $1^\circ$ scattering during passage through gold foil.
- In Geiger $-$ Marsden scattering experiment, the trajectory traced by an $\alpha-$ particle depends on.
- Number of collision.
- Number of scattered $\alpha- $ particles.
- Impact parameter.
- None of these.
- In the Geiger $-$ Marsden scattering experiment, in case of head $-$ on collision, the impact parameter should be.
- Maximum
- Minimum
- Infinite
- zero
- The fact only a small fraction of the number of incident particles rebound back in Rutherford scattering indicates that.
- Number of $\alpha-$ particles undergoing head $-$ on $-$ collision is small.
- Mass of the atom is concentrated in a small volume.
- Mass of the atom is concentrated in a large volume.
- Both $(a)$ and $(b).$
At room temperature, most of the $H-$ atoms are in ground state. When an atom receives some energy $($i.e., by electron collisions$),$ the atom may acquire sufficient energy to raise electron to higher energy state. In this condition, the atom is said to be in excited state. From the excited state, the electron can fall back to a state of lower energy emitting a photon equal to the energy difference of the orbit.
In a mixture of $He-He$ gas $(He^+$ is singleionized $He$ atom$)$.
$H-$ atoms and $He^+$ ions are excited to their respective first excited states.
Subsequently $, H-$atoms transfer their total excitation energy to $He^+$ ions $($by collisions$)$
View full solution →In a mixture of $He-He$ gas $(He^+$ is singleionized $He$ atom$)$.
$H-$ atoms and $He^+$ ions are excited to their respective first excited states.
Subsequently $, H-$atoms transfer their total excitation energy to $He^+$ ions $($by collisions$)$
- The quantum number n of the state finally populated in $He^+$ ions is.
- $2$
- $3$
- $4$
- $5$
- The wavelength of light emitted in the visible region by $He^+$ ions after collisions with $H-$ atoms is.
- $6.5 \times 10^{-7} m$
- $5.6 \times 10^{-7} m$
- $4.8 \times 10^{-7} m$
- $4.0 \times 10^{-7} m$
- The ratio of kinetic energy of the electrons for the $H-$ atoms to that of $He^+$ ion for $n = 2$ is.
- $\frac{1}{4}$
- $\frac{1}{2}$
- $1$
- $2$
- The radius of the ground state orbit of $H-$ atoms is.
- $\frac{\epsilon_0}{\text{h}\pi\text{me}^2}$
- $\frac{\text{h}^2\epsilon_0}{\pi\text{me}^2}$
- $\frac{\pi\text{me}^2}{\text{h}}$
- $\frac{2\pi\text{h}\epsilon_0}{\text{me}^2}$
- Angular momentum of an electron in $H-$ atom in first excited state is.
- $\frac{\text{h}}{\pi}$
- $\frac{\text{h}}{2\pi}$
- $\frac{2\pi}{\text{h}}$
- $\frac{\pi}{\text{h}}$
When white radiation is passed through a sample of hydrogen gas at room temperature, absorption lines are observed in Lyman series only. Explain.
The gravitational attraction between electron and proton in a hydrogen atom is weaker than the coulomb attraction by a factor of about $10^{–40}$. An alternative way of looking at this fact is to estimate the radius of the first Bohr orbit of a hydrogen atom if the electron and proton were bound by gravitational attraction. You will find the answer interesting.
View full solution →$A 12.5 eV$ electron beam is used to bombard gaseous hydrogen at room temperature. What series of wavelengths will be emitted?
View full solution →Obtain an expression for the frequency of radiation emitted when a hydrogen atom de $-$ excites from level n to level $(\text{n – ncy })$ of revolution of the electron in the orbit.
View full solution →A hydrogen atom initially in the ground level absorbs a photon, which excites it to the $n = 4$ level. Determine the wavelength and frequency of photon.
View full solution →- Using the Bohr’s model calculate the speed of the electron in a hydrogen atom in the $n = 1, 2,$ and $3$ levels.
- Calculate the orbital period in each of these levels.
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