Atoms

CBSE Class 12 Physics · every board question from this chapter, 2022–2026 · 31 of them repeated across years

• In Bohr model of hydrogen atom, the value of potential energy of an electron in n^ th orbit varies with ' n ' as2026
• In Bohr model of hydrogen atom, for large values of n, the distance between the consecutive orbits is proportional to2026
• In Bohr model of hydrogen atom, an electron makes a transition from n=4 state to n=1 state and a photon of frequency v is…2026
• The ratio of the potential energy to the kinetic energy of an electron in n^ th orbit of Bohr model of hydrogen atom is2026
• The 'distance of closest approach' of an alpha-particle is 'd' when it moves with a velocity v head-on towards the target…2026
• In Bohr model of hydrogen atom, an electron is moving in an orbit, with total energy -3.4 eV. Its angular momentum will be2026
• According to Bohr model of hydrogen atom, the time period of an electron in its n^ th orbit is proportional to2026
• The energy of an electron in an orbit in hydrogen atom is -3‧4 eV. Its angular momentum in the orbit will be:2026asked 3×
• The ratio of the de Broglie wavelengths associated with the electron revolving in the first and third orbits in hydrogen atom is:2026
• Paschen series in spectrum of hydrogen atom lies in:2026asked 3×
• The energy of an electron revolving in the n^ th orbit in Bohr model of hydrogen atom is proportional to:2026
• In Bohr model of hydrogen atom, the electron makes a transition from n=5 to n = 1 state. As a result, a photon of wavelength λ is…2026
• Reason: In Bohr model of hydrogen atom, the energy levels are discrete and quantised. Reason (R): In a hydrogen atom, the…2026asked 3×
• Draw the graph showing the variation of number of scattered alpha particles (N) detected with scattering angle ( θ ) in…2026
• Calculate the de Broglie wavelength associated with an electron revolving in the second excited state of hydrogen atom. The…2026
• In Bohr model of hydrogen atom, calculate: the radius of the innermost electron orbit, and the speed of electron in this orbit.2026
• State Bohr's second postulate and mention its significance. Prove that, in Bohr model of hydrogen atom as principal quantum…2026
• Out of the four options given, in which transition will the emitted photon have the maximum wavelength?2025
• The minimum energy required to free the electron from the ground state of the hydrogen atom is:2025
• The energy of an electron in a hydrogen atom in ground state is -13.6 eV. Its energy in an orbit corresponding to quantum number…2025asked 3×
• Assertion: In Bohr model of hydrogen atom, the angular momentum of an electron in n^ th orbit is proportional to the square root…2025asked 3×
• Assertion: The Balmer series in hydrogen atom spectrum is formed when the electron jumps from higher energy state to the ground…2025asked 3×
• Assertion: The potential energy of an electron revolving in any stationary orbit in a hydrogen atom is positive. Reason (R): The…2025asked 3×
• Assertion: In Rutherford's alpha particle scattering experiment, the presence of only few alpha particles at angle of scattering…2025asked 3×
• Define the'distance of closest approach'. An α -particle of kinetic energy K is bombarded on a thin gold foil. Derive an…2025
• In Bohr's model of hydrogen atom, find the percentage change in the radius of its orbit when an electron makes a transition from…2025
• Find the ratio of minimum to maximum wavelength of radiations emitted when electron jumps from higher energy state into ground…2025
• An electron in Bohr model of hydrogen atom makes a transition from energy level -1.51 eV to -3.40 eV. Calculate the change in the…2025
• Prove that, in Bohr model of hydrogen atom, the time period of revolution of an electron in n^ th orbit is proportional to n^3.2025
• The energy of an electron in an orbit of Bohr hydrogen atom is-3.4 eV. Find its angular momentum.2025
• Describe briefly Geiger-Marsden scattering experiment. Depict the graph showing the variation of number of scattered particles…2025
• In Bohr model of hydrogen atom, an electron is revolving in second orbit. Find the value of: (i) angular momentum of electron,…2025
• How is the necessary force provided to an electron to keep it moving in a circular orbit according to Bohr model of hydrogen…2025
• Write the mathematical forms of three postulates of Bohr's theory of the hydrogen atom. Using them prove that, for an electron…2025asked 3×
• A hydrogen atom consists of an electron revolving in a circular orbit of radius r with certain velocity v around a proton located…2025asked 3×
• The radius ( r n ) of n^ th orbit in Bohr model of hydrogen atom varies with n as2024asked 3×
• The transition of electron that gives rise to the formation of the second spectral line of the Balmer series in the spectrum of…2024asked 3×
• Energy levels A, B and C of an atom correspond to increasing values of energy i.e. E A<E B<E C. Let λ 1, λ 2 and λ 3 be the…2024asked 3×
• The energy of an electron in the ground state of hydrogen atom is -13.6 eV. The kinetic and potential energy of the electron in…2024asked 3×
• An alpha particle approaches a gold nucleus in Geiger-Marsden experiment with kinetic energy K. It momentarily stops at a…2024asked 3×
• An electron makes a transition from n=2 level to n=1 level in the Bohr model of a hydrogen atom. Its period of revolution:2024asked 3×
• In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear2024asked 3×
• Assertion: An alpha particle is moving towards a gold nucleus. The impact parameter is maximum for the scattering angle of 180^°.…2024asked 3×
• In Bohr model of hydrogen atom, find the ratio of period of revolution of the electron in the orbit n = 2 to that in the orbit n…2024
• Two energy levels of an electron in hydrogen atom are separated by 2.55 eV. Find the wavelength of radiation emitted when the…2024
• The electron in hydrogen atom is revolving with the speed of 2.2 × 10^6 m / s in an orbit of radius 0.53. Calculate the initial…2024
• The earth revolves around the sun in an orbit of radius 1.5 × 10^11 m with orbital speed 30 km / s. Find the quantum number that…2024
• Draw the graph showing variation of scattered particles detected ( N ) with the scattering angle ( θ ) in Geiger-Marsden…2024asked 3×
• State Bohr's first and second postulates. Use them to derive an expression for the radius of the n^ th orbit in a hydrogen atom.2024
• Explain the origin of the spectral lines of hydrogen atom using Bohr's theory. Draw the energy level diagram of hydrogen atom…2024
• Using Bohr's postulates, derive the expression for the radius of the n^ th orbit of an electron in a hydrogen atom. Also find the…2024
• State Bohr's second postulate for his theory of hydrogen atom. Prove that the radius of Bohr's orbit of a hydrogen atom is…2024
• State the three postulates of Bohr's theory of hydrogen atom. A hydrogen atom de-excites from level n to level ( n-1 ). Show…2024
• Write the drawbacks of Rutherford's atomic model. How did Bohr remove them? Show that different orbits in Bohr's atom are not…2024asked 2×
• Draw a schematic arrangement of Geiger-Marsden experiment. Briefly explain the conclusions drawn from the observations about the…2024
• Specify the transition of electron in the wavelength of the line in the Bohr model of hydrogen atom which gives rise to the…2023
• The ratio of the magnitude of magnetic moment to that of angular momentum, of an electron revolving around the nucleus in a…2023
• The diagram shows four energy level of an electron in Bohr model of hydrogen atom. Identify the transition in which the emitted…2023asked 2×
• The diagram shows four energy level of an electron in Bohr model of hydrogen atom. Identify the transition in which the emitted…2023
• Hydrogen atom initially in the ground state, absorbs a photon which excites it to n=5 level. The wavelength of the photon is:2023asked 3×
• A hydrogen atom makes a transition from n=5 to n=1 orbit. The wavelength of photon emitted is λ. The wavelength of photon emitted…2023
• The ratio of maximum frequency and minimum frequency of light emitted in Balmer series of hydrogen spectrum, in Bohr's model is:2023asked 3×
• The potential energy of an electron in the second excited state in hydrogen atom is:2023asked 3×
• The radius of the n^ th orbit in Bohr model of hydrogen atom is proportional to2023asked 4×
• The ground state energy of hydrogen atom is -13 · 6 eV in Bohr model. An electron makes a transition from an energy level of…2023
• What is meant by ionisation energy? Write its value for hydrogen atom. OR Define the term, mass defect. How is it related to…2023asked 3×
• The ground state energy of hydrogen atom is -13.6 eV. What is the potential energy and kinetic energy of an electron in the third…2023
• Calculate the wavelength of the second line of Lyman series in a spectrum of hydrogen atom. (Take Rydberg constant, R=1 · 1 ×…2023
• Differentiate between 'impact parameter' and 'distance of closest approach' in alpha particle scattering experiment. Identify,…2023
• Draw the energy level diagram for hydrogen atom. Mark the transitions corresponding to the series lying in the ultraviolet…2023asked 3×
• Briefly explain Geiger-Marsden experiment. Show the variation of the number of particles scattered ( N ) with scattering angle (…2023
• (i) Differentiate between 'distance of closest approach' and 'impact parameter'. (ii) Determine the distance of closest approach…2023
• (i) Write the limitations of Rutherford's model of atom. (ii) The wavelength of the second line of the Balmer series in the…2023
• Draw the graph showing the variation of the number (N) of scattered alpha particles with scattering angle ( θ ) in Geiger -…2022asked 3×
• (i) Define the terms: 'impact parameter' and 'distance of closest approach' for an α -particle in Geiger-Marsden scattering…2022asked 3×
• Define the term - Distance of closest approach. How will it be affected, for an α - particle, if kinetic energy of the particle…2022asked 2×
• State Bohr's postulate to explain stable orbits in a hydrogen atom. Prove that the speed with which the electron revolves in n^…2022asked 2×
• Draw a graph showing the variation of number of particles scattered (N) with the scattering angle θ in Geiger-Marsden experiment.…2022
• An electron in a hydrogen atom makes transitions from orbits of higher energies to orbits of lower energies. (i) When will such…2022
• The energy of a hydrogen atom in the first excited state is -3.4 eV. Find: the radius of this orbit. (Take Bohr radius =0.53 )…2022
• Use Bohr's postulate to prove that the radius of n^ th orbit in a hydrogen atom is proportional to n^2. How will the energy of a…2022
• Sketch the energy level diagram for hydrogen atom. Find the ratio of the longest and the shortest wavelength in Lyman series in…2022
• State Bohr's quantization condition for defining stationary orbits. Use the energy level diagram shown below to obtain the…2022
• The energy of hydrogen atom in an orbit is -1.51 eV. What are kinetic and potential energies of the electron in this orbit? The…2022
• An electron is in the third excited state in a hydrogen atom. It undergoes transitions to the lower energy states. What is the…2022

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