Atoms — practice questions
126 curated practice questions from Atoms (Physics Class 12, CBSE) — 107 easy, 15 medium, 4 hard. Every question includes the final answer free; step-by-step worked solutions with a free account.
- In a Rutherford scattering experiment, when a projectile of charge z 1 and mass M 1 approaches a target nucleus of…
- Energy is absorbed in the hydrogen atom giving absorption spectra when transition takes place from
- If the speed of an electron in the ground state of hydrogen atom is 2.2 10^6 m s ^ -1 , find its speed in the fourth…
- Out of the four options given, in which transition will the emitted photon have the maximum wavelength?
- The radius of electron orbit and the speed of electron in the ground state of hydrogen atom is 5.30 × 10 –11 m and 2.2…
- When an electron falls from a higher energy to a lower energy level the difference in the energies appears in the form…
- The binding energy of an electron in the ground state of He is equal to 24.6 eV. The energy required to remove both the…
- Energy levels A, B and C of an atom correspond to increasing values of energy i.e. E _ A E _ B E _ C . Let _1, _2 and…
- Hydrogen atom initially in the ground state, absorbs a photon which excites it to n = 5 level. The wavelength of the…
- Ionization potential of hydrogen atom is 13.6 eV. Hydrogen atoms in the ground state are excited by monochromatic…
- The relationship between kinetic energy ( K ) and potential energy ( U ) of electron moving in a orbit around the…
- The wavelength limit present in the Pfund series is ( R = 1.097 × 10 7 m s –1 )
- In Bohr s model of hydrogen atom, the total energy of the electron in n th discrete orbit is proportional to
- The radius of n th orbit r n in terms of Bohr radius ( a 0 ) for a hydrogen atom is given by the relation
- In the Geiger-Marsden scattering experiment the number of scattered particles detected are maximum and minimum at the…
- In Bohr model of the hydrogen atom, the potential energy of electron in the ground state is:
- A beam of beryllium nucleus ( z = 4) of kinetic energy 5.3 MeV is headed towards the nucleus of gold atom ( Z = 79)…
- What is the ratio of the shortest wavelength of the Balmer series to the shortest wavelength of the Lyman series ?
- Which of the following statements is correct for alpha particle scattering experiment?
- The impact parameter for an alpha particle approaching a target nucleus is maximum when the scattering angle ( ) is:
- Assertion (A): In Rutherford's alpha particle scattering experiment, the presence of only few alpha particles at angle…
- The diagram shows four energy level of an electron in Bohr model of hydrogen atom. Identify the transition in which the…
- The wavelength of spectral line in the Lyman series of a H-atom is 1028 Å. If instead of hydrogen, we consider…
- The moment of momentum for an electron in second orbit of hydrogen atom as per Bohr’s model is
- The shortest wavelength present in the Paschen series of spectral lines is
- Assertion (A): The Balmer series in hydrogen atom spectrum is formed when the electron jumps from higher energy state…
- The volume occupied by an atom is greater than the volume of the nucleus by a factor of about
- The radius ( r _ n ) of n ^ th orbit in Bohr model of hydrogen atom varies with n as
- Assertion (A): An alpha particle is moving towards a gold nucleus. The impact parameter is maximum for the scattering…
- In an experiment on α-particle scattering, α-particles are directed towards a gold foil and detectors are placed in…
- If muonic hydrogen atom is an atom in which a negatively charged muon (μ) of mass about 207 m e revolves around a…
- According to second postulate of Bohr model, the angular momentum ( L n ) of n th possible orbit of hydrogen atom is…
- The simple Bohr model cannot be directly applied to calculate the energy levels of an atom with many electrons. This is…
- If E is the energy of n th orbit of hydrogen atom the energy of n th orbit of He atom will be
- The transition from the state n = 3 to n = 1 in a hydrogen like atom results in ultraviolet radiation. Infrared…
- The magnetic moment ( ) of a revolving electron around the nucleus varies with principal quantum number n as
- The energy of an electron in a hydrogen atom in ground state is -13.6 eV. Its energy in an orbit corresponding to…
- Out of the following which one is not a possible energy for a photon to be emitted by hydrogen atom according to Bohr’s…
- Consider aiming a beam of free electrons towards free protons. When they scatter, an electron and a proton cannot…
- In Balmer series of emission spectrum of hydrogen, first four lines with different wavelength H α H β H γ and H δ are…
- The Rydberg formula, for the spectrum of the hydrogen atom where all terms have their usual meaning is
- If the radius of inner most electronic orbit of a hydrogen atom is 5.3 × 10 –11 m, then the radii of n = 2 orbit is
- The total energy of the electron in the ground state of hydrogen atom is -13.6 eV. The kinetic energy of the electron…
- If separation of two energy levels in an atom is 2.3 eV, then the frequency of radiation emitted when the atom transits…
- Assertion(A): The potential energy of an electron revolving in any stationary orbit in a hydrogen atom is positive…
- Bohr’s basic idea of discrete energy levels in atoms and the process of emission of photons from the higher levels to…
- An electron is revolving in the n th orbit of radius 4.2 Å, then the value of n is ( r 1 = 0.529 Å)
- If an electron in hydrogen atom is revolving in a circular track of radius 5.3 × 10 –11 m with a velocity of 2.2 × 10 6…
- In a Geiger-Marsden experiment. Find the distance of closest approach to the nucleus of a 7.7 MeV -particle before it…
- An ionised H-molecule consists of an electron and two protons. The protons are separated by a small distance of the…
- H-atom consist of a proton and an electron. If the mass of H-atom is m H , the mass of electron is m e and the mass of…
- In the Geiger-Marsden scattering experiment, in case of head-on collision the impact parameter should be
- A hydrogen atom makes a transition from n = 5 to n = 1 orbit. The wavelength of photon emitted is . The wavelength of…
- Which of the following statements is not correct according to Rutherford model?
- Specify the transition of electron in the wavelength of the line in the Bohr model of hydrogen atom which gives rise to…
- The transition of electron that gives rise to the formation of the second spectral line of the Balmer series in the…
- In a Rutherford scattering experiment, when an alpha particle of mass m _ 1 approaches a target nucleus of charge Ze…
- If an electron is revolving in its Bohr orbit having Bohr radius of 0.529 Å, then the radius of third orbit is
- In the Bohr model of the hydrogen atom, the lowest orbit corresponds to
- The potential energy of an electron in the second excited state in hydrogen atom is:
- In accordance with the Bohr’s model, the quantum number that characterises the earth’s revolution around the sun in an…
- In Rutherford's nuclear model of the atom, the entire positive charge and most of the mass of the atom are concentrated…
- When an electron jumps from the fourth orbit to the second orbit, one gets the
- Which of the following spectral series falls within the visible range of electromagnetic radiation
- Assertion(A): In Bohr model of hydrogen atom, the angular momentum of an electron in n ^ th orbit is proportional to…
- The simple Bohr model is not applicable to He 4 atom because
- A 10 kg satellite circles earth once every 2 h in an orbit having a radius of 8000 km. Assuming that Bohr’s angular…
- The electric current I created by the electron in the ground state of H atom using Bohr model in terms of Bohr radius (…
- Taking the Bohr radius as a 0 = 53 pm, the radius of Li ++ ion in its ground state, on the basis of Bohr’s model, will…
- The radius of the n th orbit in Bohr model of hydrogen atom is proportional to:
- The energy of an electron in the ground state of hydrogen atom is -13.6 eV. The kinetic and potential energy of the…
- The ground state energy of hydrogen atom is –13.6 eV. The kinetic energy of the electron in this state is
- A proton and an alpha particle having equal velocities approach a target nucleus. They come momentarily to rest and…
- According to Bohr’s theory, the wave number of last line of Balmer series is ( Given R = 1.1 × 10 7 m –1 )
- The ratio of the speed of the electron in the ground state of hydrogen atom to the speed of light in vacuum is
- Paschen series of atomic spectrum of hydrogen gas lies in:
- The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission…
- The value of ionisation energy of the hydrogen atom is
- A hydrogen atom initially in the ground level absorbs a photon and is excited to n = 4 level then the wavelength of…
- An electron is in an excited state in a hydrogen like atom. It has a total energy of –3.4 eV. The kinetic energy of the…
- The graph of the total number of α-particles scattered at different angles in a given interval of time for α-particle…
- Which of the following statements is true for hydrogen atom ?
- Ratio of longest wavelengths corresponding to Lyman and Balmer series in hydrogen spectrum is
- In Geiger-Marsden scattering experiment the trajectory traced by an a -particle depends on
- The minimum energy that must be given to a H atom in ground state so that it can emit an H γ line in Balmer series is
- When an atomic gas or vapour is excited at low pressure, by passing an electric current through it then
- In which of the following Bohr’s orbit ( n ) a hydrogen atom emits the photons of lowest frequency?
- Energy E of a hydrogen atom with principal quantum number n is given by E= -13.6 n^ 2 eV The energy of a photon ejected…
- From quantisation of angular momentum, one gets for hydrogen atom, the radius of the n th orbit as r_ n = ( n^ 2 m_ e )…
- In the -particle scattering experiment, the shape of the trajectory of the scattered -particles depend upon:
- The total energy ( E n ) of the electron in the stationary states in the n th orbit of the hydrogen atom is
- An alpha nucleus of energy 1 2 m v^ 2 bombards a heavy nuclear target of charge Ze. Then the distance of closest…
- Two H atoms in the ground state collide inelastically. The maximum amount by which their combined kinetic energy is…
- In an atom the ratio of radius of orbit of electron to the radius of nucleus is
- Suppose an electron is attracted towards the origin by a force k / r , where k is a constant and r is the distance of…
- In the question number 37, the frequency of emitted photon due to the given transition is (Take, h = 6.64 × 10 –34 J s…
- In the question number 43, find the potential energy of electron (in Joule) in the given state.
- The wavelength of the first line of Lyman series is 1215 Å, the wavelength of first line of Balmer series will be
- Which of the following is not correct about Bohrs model of the hydrogen atom?
- The shortest wavelength in the Balmer series is (Take R = 1.097 × 10 7 m –1 )
- When a hydrogen atom is raised from the ground state to an excited state,
- If 13.6 eV energy is required to separate a hydrogen atom into a proton and an electron, then the orbital radius of…
- The ionisation energy of the hydrogen atom, in Bohr model, is:
- The wavelength of the first line of Lyman series of hydrogen atom is equal to that of the second line of Balmer series…
- In the question number 52, if ground state energy of electron is –13.6 eV then what is the ground state energy of…
- The first line of the Lyman series in a hydrogen spectrum has a wavelength of 1210 Å. The corresponding line of a…
- In Balmer series of hydrogen atom, as the wavelength of spectral lines decreases, they appear
- Positronium is like a H atom with the proton replaced by positron (a positively charged antiparticle of the electron…
- For ground state, the electron in the H-atom has an angular momentum= h according to the simple Bohr model. Angular…
- The ratio of maximum frequency and minimum frequency of light emitted in Balmer series of hydrogen spectrum, in Bohr's…
- The relation between the orbit radius and the electron velocity for a dynamically stable orbit in a hydrogen atom is…
- In Bohr model of the hydrogen atom, the kinetic energy of an electron in n =2 orbit is:
- An electron in a hydrogen atom makes a transition from n = n 1 to n = n 2 . The time period of the electron in the…
- Let E_ n = -m e^ 4 8 _ 0 ^ 2 n^ 2 h^ 2 be the energy of the n th level of H-atom. If all the H-atoms are in the ground…
- The volume occupied by an atom is greater than the volume of the nucleus by a factor of about:
- If the wavelength of the first line of the Balmer series of hydrogen is 6561 Å, the wavelength of the second line of…
- In which of the following systems will the radius of the first orbit ( n = 1) be minimum ?
- A triply ionized beryllium (Be 3+ ) has the same orbital radius as the ground state of hydrogen. Then the quantum state…
- The de-Broglie wavelength of an electron in the first Bohr orbit is
- The energy required to excite an electron in hydrogen atom to its first excited state is
- In the question number 30, the value of velocity of the revolving electron is
- If υ 1 is the frequency of the series limit of Lyman series, υ 2 is the frequency of the first line of Lyman series and…
- If n is the orbit number of the electron in a hydrogen atom, the correct statement among the following is
- The binding energy of a H-atom, considering an electron moving around a fixed nuclei (proton), is B=- m e^ 4 8 n^ 2 _ 0…
- The minimum energy required to free the electron from the ground state of the hydrogen atom is:
- Hydrogen atom from excited state comes to the ground state by emitting a photon of wavelength . If R is the Rydberg…