Atomic Structure — practice questions

212 curated practice questions from Atomic Structure (Chemistry JEE Main, NTA Exams) — 128 easy, 60 medium, 24 hard. Every question includes the final answer free; step-by-step worked solutions with a free account.

• An electron has kinetic energy 2.8 × 10 –23 J de–Broglie wavelength will be nearly(m e = 9.1 × 10 –31 kg)
• The radius of the 2 nd orbit of Li ^ 2+ is . The expected radius of the 3 rd orbit of Be ^ 3+ is (Jee Main 2023)
• Given below are two statements: Statement I: The orbitals having same energy are called as degenerate orbitals…
• Minimum number of photons of light of wavelength 4000Å, which provide 1J energy :
• A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then
• The ionization energy of hydrogen atom is 13.6 eV. The energy required to excite the electron in a hydrogen atom from…
• The wavelength of the first spectral line in the Balmer series of hydrogen atom is 6561 A . The wavelength of the…
• The outer electronic configuration of Gd (Atomic No = 64) is:
• Which electronic configuration does not follow the Pauli’s exclusion principle ?
• Increase in the frequency of the incident radiations increase the :
• Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from n = 4 to n…
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: The 19 th…
• If the threshold frequency of a metal for photoelectric effect is ν 0 , then which of the following will not happen ?
• The wavelength of a cricket ball weighing 100 g and travelling with a velocity of 50 m/s is
• The quantum number not obtained from Schrodinger equation is
• A cricket ball of 0.5 kg is moving with a velocity of 100 ms –1 . The wavelength associated with its motion is
• The threshold wavelength for photoelectric effect on sodium is 5000 Å. Its work function is :
• The energy of an electron in the first Bohr orbit of H atom is –13.6 eV. The possible energy value(s) of the excited…
• The energy required to dislodge electron from excited isolated H-atom, IE 1 = 13.6 eV is
• The correct decreasing order of energy, for the orbitals having, following set of quantum numbers: A. n = 3, l = 0, m =…
• The de Broglie wavelength of a tennis ball of mass 66 g moving with the velocity of 10 metres per second is…
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• The energy of an electron in the first Bohr orbit of hydrogen atom is 2.18 10^ -18 J . Its energy in the third Bohr…
• The relation between energy of a radiation and its frequency was given by :
• The correct ground state electronic configuration of chromium atom (Z = 24) is
• A certain transition in H spectrum from an excited state to the ground state in one or more steps gives rise to a total…
• A 3d-electron having s = +1/2 can have a magnetic quantum no :
• The energy of one mole of photons of radiation of wavelength 300 nm is (Given: h = 6.63 x 10 –34 J s, N A = 6.02 x 10…
• The maximum kinetic energy of photoelectrons emitted from a surface when photons of energy 6 eV fall on it is 4 eV. The…
• Consider the following ions 1 . Ni 2+ 2 . Co 2+ 3 . Cr 2+ 4 . Fe 3+ (Atomic number : Cr = 24, Fe = 26, Co = 27 and Ni =…
• For an electron, if the uncertainty in velocity ( v ) is the uncertainty in its position ( x ) is given by :
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• An electron jumps from 6th energy level to 3rd energy level in H-atom, how many lines belong to visible region ?
• In the lowest energy level of hydrogen atom, the electron has the angular momentum
• Find the wavelength associated with an electron moving with a velocity of 10 6 m/sec? Given: h=6.63 10^ -34 ~J
• The d-orbital with the orientation along X and Y axes is called :
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• For which one of the following sets of four quantum numbers an electron will have the highest energy array lllll & n &…
• Which one of the following sets of ions represents the collection of isoelectronic species?
• Which of the following atoms and ions are isoelectronic i.e. have the same number of electrons with the neon atom
• The number of photons of light of v = 2.5 × 10 6 m –1 necessary to provide 1 J of energy are
• Ultraviolet light of 6.2 eV falls on aluminium surface (work function = 4.2 eV). The kinetic energy (in joule) of the…
• Given below are two statements. STATEMENT - 1: Photoelectric effect establishes quantum nature of light. STATEMENT - 2…
• An isotone of 32 Ge 76 is (i) 32 Ge 77 (ii) 33 As 77 (iii) 34 Se 77 (iv) 34 Se 78
• The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from…
• The radial part of wave function depends on the quantum numbers:
• The correct designation of an electron with n = 4, l = 3, m = 2, and s = 1/2 is :
• The de–Broglie wavelength associated with a material particle is
• How many spherical nodes are present in 4s orbital in a hydrogen atom ?
• .The radius of hydrogen atom is 0.53 A . The radius of 3 Li 2 + is of:
• Given below are the quantum numbers for 4 electrons. A. n = 3, l = 2, m l = 1, m s = +1/2 B. n = 4, l = 1, m l = 0, m s…
• Ratio of frequency of revolution of electron in the second excited state of He + and second state of hydrogen is
• Azimuthal quantum number for the last electron in Na atom is
• The largest wavelength in the ultraviolet region of the hydrogen spectrum is 122 nm. The smallest wavelength in the…
• The number of nodes possible in radial wave function of 3d orbital is
• Which one of the following represents collection of isoelectronic species? (At. numbers Cs = 55, Br = 35)
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: The…
• A Cesium photocell, with a steady potential difference of 60 V across it, is illuminated by a bright point source of…
• The four quantum numbers for the electron in the outermost orbital of potassium (atomic no. 19) are (Jee Main 2024)
• For any given series of spectral lines of atomic hydrogen, let v = v _ m a x - v _ m i n be the difference in maximum…
• The increasing order (lowest first) for the values of e m ( charge mass ) for electron (e), proton (p), neutron (n) and…
• Which of the following is not a characteristic of Planck’s quantum theory of radiation ?
• When photon of energy 4.0 eV strikes the surface of a metal A, the ejected photoelectrons have maximum kinetic energy T…
• Rutherford’s scattering experiment is related to the size of the
• Which of the following has maximum number of unpaired electrons ?
• If uncertainty in the position of an electron is zero, the uncertainty in its momentum would be
• The pair, in which ions are isoelectronic with Al 3+ is: (JEE Main 2022)
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• Identify the incorrect statement from the following. (JEE Main 2022)
• The relation between the wavelength of radiation (λ) and the principal quantum number n, when an electron jumps from…
• The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of…
• The ionization energy of H atom is 13.6 eV. The ionization energy of Li 2+ ion will be
• The correct set of four quantum numbers for the valence electron of rubidium atom is: (Jee Main 2024)
• Which of the following sets of quantum number is correct for an electron in 4f orbital ?
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT - 1…
• Hydrogen [ _ 1 H ^ 1 ] , Deuterium [1 H ^ 2 ] , singly ionized Helium [ _ 2 He ^ 4 ]^ + and doubly ionized lithium [3^…
• Magnetic quantum number for the last electron in sodium is :
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: There are…
• Light from a monochromatic source of wavelength, is incident normally on a small photo-sensitive surface of area S…
• Which of the following lines of the H-atom spectrum belongs to the Balmer series ?
• The electrons identified by n and 1 (i) n = 4, 1 = 1 (ii) n = 4, 1 = 0 (iii) n = 3, 1 = 2 (iv) n = 3, 1 = 1 can be…
• Ionisation potential of hydrogen atom is 13.6 eV. If hydrogen atom in the ground state is excited by monochromatic…
• An electron in H-atom is moving with a kinetic energy of 5.45×10 –19 J. What will be energy level for this electron ?
• What will be the photon flux incident on an unit square metre of the Earth's surface, if the intensity of light…
• The number of radial and angular nodes in 4d orbital are, respectively (JEE Main 2022)
• The energy of hydrogen atom in its ground state is -13.6 eV. The energy of the level corresponding to the quantum…
• Consider the following pairs of electrons (A) (a) n-3,1-1, m_ 1 -1, m_ 1 =+ 1 2 (b) n-3,1-2, m_ 1 -1, m_ 1 =+ 1 2 (B)…
• The ratio of energies required to remove an electron from the first orbit and the second orbit for the hydrogen atom is:
• The energy E corresponding to intense yellow line of sodium of 589 nm is :
• According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents the most…
• How many spectral lines are produced in the spectrum of hydrogen atom from 5th energy level ?
• Discovery of the nucleus of an atom was due to the experiment carried out by
• The wavenumber for the shortest wavelength transition in the Balmer series of atomic hydrogen is
• The e/m for positive rays in comparison to cathode rays is :
• The electric potential between a proton and an electron is given by V = V 0 ln (r / r 0 ), where r 0 is a constant…
• Arrange the following orbitals in decreasing order of energy? (A) n = 3, l = 0, m = 0 (B) n = 4, l = 0, m = 0 (C) n =…
• Energy of H-atom in the ground state is -13.6 eV, hence energy of the second excited state is:
• In hydrogen spectrum, the series of lines appearing in ultraviolet region of electromagnetic spectrum are called
• Hydrogen has three isotopes: protium ( 1 H), deuterium ( 2 H or D) and tritium ( 3 H or T). They have nearly the same…
• In a multi-electron atom, which of the following orbitals described by the three quantum numbers will have the same…
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: The…
• The Heisenbergs Uncertainty Principle states that ........... .
• The difference in wavelength of second and third lines of Balmer series in the atomic spectrum is
• The shortest wavelength of hydrogen atom in Lyman series is . The longest wavelength in Balmer series of He ^ + is (Jee…
• Match List-I with List-II. array |l|l|l|l| C. & Paschen & III. & Infrared region D. & Pfund & IV. & Visible region…
• Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A)…
• Suppose the potential energy between an electron and proton at a separation r is given by U=- k e^ 2 Z r , where k is a…
• The number of electrons in a neutral atom of an element is equal to its :
• The energy of second Bohr orbit in the hydrogen atom is –3.4 eV. The energy of fourth orbit of He + ion would be
• The frequency of a wave of light is 12 × 10 14 s –1 . The wave number associated with this light is
• In photoelectric effect the number of photo-electrons emitted is proportional to :
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: 1p-orbital…
• The orbital angular momentum of an electron revolving in an orbit in which its energy is -3.4 eV is:
• If p is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having…
• Which one of the following constitutes a group of the isoelectronic species?
• A He + atom returns from its 4 th excited state to its 3 rd excited state and from 3 rd excited state to first 2 nd…
• The number of photons emitted in 10 hours by a 60 W sodium lamp (λ of photon = 6000 Å)
• The Bohr orbit radius for the hydrogen atom (n = 1) is approximately 0.530 Å. The radius for the first excited state (n…
• The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal…
• Maximum number of electrons that can be accommodated in shell with n = 4 are: (Jee Main 2023)
• The potential energy of an electron in hydrogenation is -3.02 eV, its kinetic energy will be:
• Rank the following types of radiations from the highest energy to the lowest…
• For each value of , the number fo m _ s values are
• The line spectrum of He + ion will resemble that of:
• An electron with velocity v is found to have a certain value of de Broglie wavelength. The velocity that the neutron…
• If the energy of a photon corresponding to a wavelength of 6000 A is 3.32 x 10 -19 Joule, the photon energy for a…
• The wave function ( ) of 2s is given by _ 2 s = 1 2 2 ( 1 a_ 0 )^ 1 2 (2- r a_ 0 ) e^ - r 2 a_ 0 At r=r_ 0 , radial…
• If uncertainty in the measurement of position and momentum of an electron are equal then uncertanity in the measurement…
• The wavelength of a spectral line for an electronic transition is inversely related to:
• The wavelengths involved in the spectrum of deuterium ( 1 D 2 ) are slightly different from that of hydrogen spectrum…
• The frequency of a green light is 6 × 10 14 Hz. Its wavelength is :
• The wave number of the first line of Balmer series of H atom is 15200 cm –1 . What is the wave number of the first line…
• If the work function for a certain metal is 3.2 x 10 -19 J and it is illuminated with light of frequency v = 8 x 10 14…
• The time period of revolution of electron in its ground state orbit in a hydrogen atom is 1.6 10^ -15_ 5 . The…
• Which of the following pair is not isoelectronic species? (At. no. Sm, 62; Er, 68: Yb, 70: Lu, 71; Eu, 63: Tb, 65; Tm…
• Presence of three unpaired electrons in phosphorus atom can be explained by
• Which of the following has maximum number of unpaired electron (atomic number of Fe is 26)
• The correct set of four quantum numbers for the valence electrons of rubidium atom (Z=37) is:
• The electronic configuration of Einsteinium is: (Given atomic number of Einsteinium = 99). (Jee Main 2024)
• Choose the incorrect statement about Dalton's atomic theory. (Jee Main 2024)
• The following particles are moving with the same velocity, then maximum de-Broglie's wavelength will be for:
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: In…
• If the radius of the 3 rd Bohr’s orbit of hydrogen atom is r 3 and the radius of 4 th Bohr’s orbit is r 4 . Then: (JEE…
• The velocity of light is 3.0 × 10 8 ms –1 . Which value is closest to the wavelength in nanometres of a quantum of…
• An electron and a neutron can have same (i) kinetic energy, (ii) momentum and (iii) speed. Which of the particle has…
• Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. (JEE Main 2022)…
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• Which wave property is directly proportional to energy of electromagnetic radiation :
• In a Bohr’s model of atom when an electron jumps from n = 1 to n = 3, how much energy will be emitted or absorbed (1erg…
• Given below are two statements. STATEMENT - 1: When ultraviolet light is incident on a photocell, its stopping…
• The position of a proton is measured with an accuracy of 1.00 10^ -11 ~m . Find the uncertainty in the proton's…
• If the total energy of an electron in a hydrogen-like element in an excited state is -3.4 eV then the de-Broglie…
• The maximum number of 4d-electrons having spin quantum number s=+ 1 2 are
• Which of the following sets of quantum numbers is not allowed? (JEE Main 2022)
• The quantum numbers for the outermost electron of an element are given below n =2, =0, ~m =0, ~m _ s =+ 1 2 The atom is
• If the value of (n+n) is more than 3 and less than 6, what will be the possible number of orbitals:
• According to Bohr's theorem, the electronic energy of hydrogen atom in the n th orbit of Bohr model is given by .E_ n…
• Whenever a hydrogen atom emits a photon in the Balmer series, it:
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: Electron…
• According to Bohr's theory, the angular momentum of an electron in 5th orbit is:
• Match List-I with List-II. Choose the correct answer from the options given below: (Jee Main 2024)
• The third line in Balmer series corresponds to an electronic transition between which Bohr’s orbits in hydrogen atom
• When light of wavelength 300 nm falls on a photoelectric emitter, photoelectrons are liberated. For another emitter…
• A photocell is illuminated by a small bright source placed 2 m away. When the same source of light is placed 4 m away…
• A ball of mass 200g is moving with a velocity of 10m sec –1 . If the error in measurement of velocity is 0.1%, the…
• The figure shows a plot of photo current versus anode potential for a photo sensitive surface for three different…
• When electrons in N shell of excited hydrogen atom return to ground state, the number of possible lines spectrum is :
• According to Bohr model, angular momentum of an electron in the 3rd orbit is :
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT-1…
• If the radius of the first orbit of hydrogen atom is a_ 0 , then de Broglie’s wavelength of electron in 3 rd orbit is…
• In a photoelectric experiment photons of energy 5 eV are incident on a metal surface. They liberate electrons which are…
• Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A: In…
• The number of radial node/s for 3p orbital is: (Jee Main 2024)
• If the electron in a hydrogen atom jumps from an orbit with level n 1 = 2 to an orbit with level n 2 = 1, the emitted…
• A subshell with n = 6, l = 2 can accommodate a maximum of
• Given below are two statements: Statement I: According to Bohr's model of hydrogen atom, the angular momentum of an…
• A compound of vanadium has magnetic moment of 1.73 B.M. The electronic configuration of the vanadium ion in the…
• When photons of energy 4.25 eV strike the surface of a metal A, the ejected photoelectrons have maximum kinetic energy…
• Which of the following is the correct plot for the probability density ^ 2 (r) as a function of distance ‘r’ of the…
• A radiation of 253.7 nm strikes the surface of a metal and ejected electrons are stopped by 0.24 eV. The work function…
• The correct set of quantum numbers for the unpaired electron of chlorine atom is array lllll & n & & ~m & ~s (a) & 3 &…
• Mass of neutron is .............. times the mass of electron.
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: The free…
• Compare the energies of following sets of quantum numbers for multi electron system. (Jee Main 2024) (A) n = 4, 1 = 1…
• The de-Broglie's wavelength of an electron in the first Bohr's orbit is equal to
• According to (n + l ) rule after completing ‘np’ level the electron enters to :
• The electronic configuration for Neodymium is: [Atomic number for Neodymium 60]. (Jee Main 2024)
• There are n 1 photons of frequency v_ 1 in a beam of light. In a equally energetic beam there are n 2 photons of…
• The number of s-electrons present in an ion with 55 protons in its unipositive state is (Jee Main 2023)
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. Assertion: An orbital…
• A beam of light of wavelength 400 nm and power 1.55 mW is directed at the cathode of a photoelectric cell (given h…
• Consider the following statements: (A) The principal quantum number 'n' is a positive integer with values of 'n' = 1…
• The de-Broglie's wavelength associated with an electron, when the kinetic energy of electron is tripled changes by a…
• The line spectrum observed when electron jumps from higher level to M level is known as
• Given below are two statements. One is labelled as Assertion and the other is labelled as Reason. STATEMENT - 1…
• Which of the following statements are correct? (A) The electronic configuration of Cr is [Ar] 3d 5 4s 1 . (B) The…
• Which of the following represent the correct set of the four quantum numbers of a 4d electron? 4, 3, 2, + ½ 4, 2, -2, …
• What transition in He + ion shall have the same wave number as the first line in Balmar series of H atom ?
• The de-Broglie's wavelength of an electron in the first Bohr orbit is:
• Out of a photon and an electron the equation E=p c is valid for
• The total spin and magnetic moment for the atom with atomic number 7 are
• Nitrogen has the electronic configuration 1 ~s ^ 2 , 2 ~s ^ 2 2 p _ x ^ 1 2 p_ y ^ 1 2 p_ z ^ 1 and not 1 ~s ^ 2 , 2 ~s…
• The de-Broglie's wavelength of a ball of mass 120 g moving at a speed of 20 m/s is
• The incorrect postulates of the Dalton's atomic theory are: (Jee Main 2024) (A) Atoms of different elements differ in…
• The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state 1…
• It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power 'n' i.e. v^ n…
• The energy of a photon is 10 eV. The momentum of a photon is
• When a gold sheet is bombarded by a beam of α–particles, only a few of them get deflected whereas most go straight…
• The circumference of the 4 th orbit of hydrogen is 5.32 nm. The wavelength of electron revolving in the first Bohr…
• The ratio of the difference in energy between the first and the second Bohr orbit to that between second and third Bohr…
• The binding energy of electrons in a metal is 193 kJ mol -1 . The threshold frequency of the metal is:

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