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Structure of Atom

191 questions · Chemistry · JEE Main
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Structure of Atom

191 questions · Chemistry · JEE Main

  1. According to Bohr's model of hydrogen atom, which of the following statement is incorrect?2025 · 2 Apr · Shift 1 · Q16 · MCQ
  2. Which of the following statements are true? (A) The subsidiary quantum number l describes the shape of the orbital occupied by the electron. (B) is the boundary surface diagram of the 2px​ orbital. (C) The + and - signs in… Includes diagram2025 · 2 Apr · Shift 2 · Q8 · MCQ
  3. Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?2025 · 3 Apr · Shift 1 · Q5 · MCQ
  4. For electrons in ' 2 s ' and ' 2 p ' orbitals, the orbital angular momentum values, respectively are :2025 · 3 Apr · Shift 2 · Q17 · MCQ
  5. Which one of the following about an electron occupying the 1 s orbital in a hydrogen atom is incorrect? (Bohr's radius is represented by a0​)2025 · 4 Apr · Shift 1 · Q3 · MCQ
  6. Consider the ground state of chromium atom (Z=24). How many electrons are with Azimuthal quantum number l=1 and l=2 respectively ?2025 · 4 Apr · Shift 2 · Q6 · MCQ
  7. Which of the following statements are correct, if the threshold frequency of caesium is 5.16×1014 Hz ? A. When Cs is placed inside a vacuum chamber with an ammeter connected to it and yellow light is focused on Cs ,… Includes diagram2025 · 7 Apr · Shift 1 · Q14 · MCQ
  8. The extra stability of half-filled subshell is due to : (A) Symmetrical distribution of electrons (B) Smaller coulombic repulsion energy (C) The presence of electrons with the same spin in non-degenerate orbitals (D) Larger exchange energy…2025 · 7 Apr · Shift 2 · Q18 · MCQ
  9. The energy of an electron in the first Bohr orbit of the H-atom is -13.6 eV. The magnitude of energy value of an electron in the first excited state of Be3+ is ​ eV (nearest integer value).2025 · 8 Apr · Shift 2 · Q22 · Numerical
  10. Correct statements for an element with atomic number 9 are: A. There can be 5 electrons for which ms​=+21​ and 4 electrons for which ms​=−21​. B. There is only one electron in pz​ orbital. C. The last electron…2025 · 8 Apr · Shift 2 · Q5 · MCQ
  11. Radius of the first excited state of Helium ion is given as : a0​→ radius of first stationary state of hydrogen atom.2025 · 22 Jan · Shift 1 · Q18 · MCQ
  12. Given below are two statements : Statement (I) : A spectral line will be observed for a 2px​→2py​ transition. Statement (II) : 2px​ and 2py​ are degenerate orbitals. In the light of the above…2025 · 22 Jan · Shift 2 · Q19 · MCQ
  13. Heat treatment of muscular pain involves radiation of wavelength of about 900 nm . Which spectral line of H atom is suitable for this? Given : Rydberg constant RH​=105 cm−1, h=6.6×10−34 J s,c=3×108 m/s)…2025 · 23 Jan · Shift 1 · Q19 · MCQ
  14. Given below are two statements : Statement (I) : For a given shell, the total number of allowed orbitals is given by n2. Statement (II) : For any subshell, the spatial orientation of the orbitals is given by −l to +l values…2025 · 23 Jan · Shift 2 · Q16 · MCQ
  15. Given below are two statements about X-ray spectra of elements : Statement (I) : A plot of v​(v= frequency of X-rays emitted) vs atomic mass is a straight line. Statement (II) : A plot of v(u= frequency of X-rays emitted) vs…2025 · 23 Jan · Shift 2 · Q18 · MCQ
  16. For hydrogen atom, the orbital/s with lowest energy is/are : (A) 4s(B) 3px​(C) 3 dx2−y2​(D) 3 dz2​(E) 4pz​ Choose the correct answer from the options given below :2025 · 24 Jan · Shift 2 · Q19 · MCQ
  17. In a multielectron atom, which of the following orbitals described by three quantum numbers will have same energy in absence of electric and magnetic fields? A. n=1,l=0, m1​=0 B. n=2,l=0, m1​=0…2025 · 28 Jan · Shift 1 · Q8 · MCQ
  18. Which of the following is/are not correct with respect to energy of atomic orbitals of hydrogen atom? (A) 1s < 2p < 3d < 4s (B) 1s < 2s = 2p < 3s = 3p (C) 1s < 2s < 2p < 3s < 3p (D) 1s < 2s < 4s < 3d…2025 · 28 Jan · Shift 2 · Q8 · MCQ
  19. If a 0 is denoted as the Bohr radius of hydrogen atom, then what is the de-Broglie wavelength (λ) of the electron present in the second orbit of hydrogen atom? [n : any integer]2025 · 29 Jan · Shift 1 · Q9 · MCQ
  20. For hydrogen like species, which of the following graphs provides the most appropriate representation of E vs Z plot for a constant n? [E : Energy of the stationary state, Z : atomic number, n = principal quantum number]2025 · 29 Jan · Shift 2 · Q14 · MCQ
  21. Given below are two statements : Statement (I): It is impossible to specify simultaneously with arbitrary precision, both the linear momentum and the position of a particle. Statement (II) : If the uncertainty in the measurement of…2025 · 29 Jan · Shift 2 · Q16 · MCQ
  22. According to the wave-particle duality of matter by de-Broglie, which of the following graph plot presents most appropriate relationship between wavelength of electron (λ) and momentum of electron (p)?2024 · 1 Feb · Shift 1 · Q13 · MCQ
  23. In case of isoelectronic species the size of F−,Ne and Na+ is affected by :2024 · 1 Feb · Shift 1 · Q7 · MCQ
  24. The number of radial node/s for 3p orbital is :2024 · 1 Feb · Shift 2 · Q15 · MCQ
  25. The de-Broglie's wavelength of an electron in the 4th  orbit is ​πa0​. (a0​= Bohr's radius)2024 · 4 Apr · Shift 1 · Q27 · Numerical
  26. Choose the Incorrect Statement about Dalton's Atomic Theory2024 · 4 Apr · Shift 2 · Q12 · MCQ
  27. The maximum number of orbitals which can be identified with n=4 and ml​=0 is ​.2024 · 4 Apr · Shift 2 · Q21 · Numerical
  28. The value of Rydberg constant (RH​) is 2.18×10−18 J. The velocity of electron having mass 9.1×10−31 kg in Bohr's first orbit of hydrogen atom = ​×105 ms−1…2024 · 5 Apr · Shift 1 · Q27 · Numerical
  29. The incorrect postulates of the Dalton's atomic theory are : (A) Atoms of different elements differ in mass. (B) Matter consists of divisible atoms. (C) Compounds are formed when atoms of different element combine in a fixed ratio. (D) All…2024 · 5 Apr · Shift 1 · Q3 · MCQ
  30. In an atom, total number of electrons having quantum numbers n=4,∣ ml​∣=1 and ms​=−21​ is ​.2024 · 5 Apr · Shift 2 · Q21 · Numerical
  31. Frequency of the de-Broglie wave of electron in Bohr's first orbit of hydrogen atom is ​×1013 Hz(nearest integer). [Given : RH​(Rydberg constant) =2.18×10−18 J,h…2024 · 6 Apr · Shift 1 · Q30 · Numerical
  32. For hydrogen atom, energy of an electron in first excited state is −3.4 eV,K.E. of the same electron of hydrogen atom is x eV. Value of x is ​×10−1 eV…2024 · 6 Apr · Shift 2 · Q24 · Numerical
  33. A hypothetical electromagnetic wave is show below. The frequency of the wave is x×1019 Hz. x=​ (nearest integer) Includes diagram2024 · 8 Apr · Shift 1 · Q24 · Numerical
  34. Wavenumber for a radiation having 5800 Ao​ wavelength is x×10 cm−1 The value of x is ​. (Integer answer)2024 · 8 Apr · Shift 2 · Q29 · Numerical
  35. Compare the energies of following sets of quantum numbers for multielectron system. (A) n=4,1=1(B) n=4,1=2(C) n=3,l=1(D) n=3,1=2(E) n=4,1=0 Choose the correct answer from the…2024 · 9 Apr · Shift 1 · Q17 · MCQ
  36. The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 'A' ×1012 hertz and that has a radiant intensity in that direction of ′B′1​, watt per…2024 · 9 Apr · Shift 2 · Q10 · MCQ
  37. Based on Heisenberg's uncertainty principle, the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter 10−15 m is ​×109 ms−1(nearest…2024 · 9 Apr · Shift 2 · Q21 · Numerical
  38. The number of electrons present in all the completely filled subshells having n=4 and s=+21​ is ​. (Where n= principal quantum number and s= spin quantum number)2024 · 27 Jan · Shift 1 · Q28 · Numerical
  39. The correct set of four quantum numbers for the valence electron of rubidium atom (Z=37) is :2024 · 29 Jan · Shift 1 · Q10 · MCQ
  40. Match List I with List II Choose the correct answer from the options given below: Includes table2024 · 29 Jan · Shift 2 · Q6 · MCQ
  41. Given below are two statements : Statement (I) : The orbitals having same energy are called as degenerate orbitals. Statement (II) : In hydrogen atom, 3p and 3d orbitals are not degenerate orbitals. In the light of the above statements,…2024 · 30 Jan · Shift 1 · Q12 · MCQ
  42. Number of spectral lines obtained in He+ spectra, when an electron makes transition from fifth excited state to first excited state will be2024 · 30 Jan · Shift 2 · Q23 · Numerical
  43. The ionization energy of sodium in  kJ mol−1, if electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodium atom is ​.2024 · 31 Jan · Shift 1 · Q23 · Numerical
  44. The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) are2024 · 31 Jan · Shift 2 · Q13 · MCQ
  45. Electrons in a cathode ray tube have been emitted with a velocity of 1000 m s −1. The number of following statements which is/are true​ about the emitted radiation is ​. Given : h=6×10−34 J s,me​=9×10−31 kg…2023 · 1 Feb · Shift 1 · Q13 · Numerical
  46. Which one of the following sets of ions represents a collection of isoelectronic species? (Given : Atomic Number : F:9,Cl:17,Na=11,Mg=12,Al=13,K=19,Ca=20,Sc=21)2023 · 1 Feb · Shift 2 · Q10 · MCQ
  47. The wavelength of an electron of kinetic energy 4.50×10−29 J is ​×10−5 m. (Nearest integer) Given : mass of electron is 9×10−31 kg, h =6.6×10−34 J s2023 · 6 Apr · Shift 1 · Q15 · Numerical
  48. If the radius of the first orbit of hydrogen atom is α0​, then de Broglie's wavelength of electron in 3rd  orbit is :2023 · 6 Apr · Shift 2 · Q5 · MCQ
  49. The number of atomic orbitals from the following having 5 radial nodes is ​. 7s,7p,6s,8p,8d2023 · 8 Apr · Shift 2 · Q19 · Numerical
  50. Henry Moseley studied characteristic X-ray spectra of elements. The graph which represents his observation correctly is Given v= frequency of X-ray emitted Z = atomic number2023 · 8 Apr · Shift 2 · Q5 · MCQ
  51. The number of incorrect statement/s about the black body from the following is ​ (A) Emit or absorb energy in the form of electromagnetic radiation. (B) Frequency distribution of the emitted radiation depends on…2023 · 10 Apr · Shift 1 · Q19 · Numerical
  52. The electron in the nth  orbit of Li2+ is excited to (n+1) orbit using the radiation of energy 1.47×10−17 J(as shown in the diagram). The value of n is ​… Includes diagram2023 · 10 Apr · Shift 2 · Q17 · Numerical
  53. Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : In the photoelectric effect, the electrons are ejected from the metal surface as soon as the beam of light of frequency…2023 · 11 Apr · Shift 1 · Q4 · MCQ
  54. The number of correct statements from the following is ​. A. For 1s orbital, the probability density is maximum at the nucleus B. For 2s orbital, the probability density first increases to…2023 · 11 Apr · Shift 2 · Q19 · Numerical
  55. Values of work function (W 0​) for a few metals are given below The number of metals which will show photoelectric effect when light of wavelength 400 nm falls on it is ​ Given: h=6.6×10−34 J s… Includes table2023 · 12 Apr · Shift 1 · Q16 · Numerical
  56. 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 orbit is ​.2023 · 13 Apr · Shift 1 · Q13 · MCQ
  57. The orbital angular momentum of an electron in 3 s orbital is 2πxh​. The value of x is ​ (nearest integer)2023 · 13 Apr · Shift 2 · Q17 · Numerical
  58. The total number of isoelectronic species from the given set is ​. O2−,F−,Al,Mg2+,Na+,O+,Mg,Al3+,F2023 · 15 Apr · Shift 1 · Q23 · Numerical
  59. Given below are two statements: Statement I : According to Bohr's model of hydrogen atom, the angular momentum of an electron in a given stationary state is quantised. Statement II : The concept of electron in Bohr's orbit, violates the…2023 · 15 Apr · Shift 1 · Q8 · MCQ
  60. It is observed that characteristic X-ray spectra of elements show regularity. When frequency to the power "n" i.e. vn of X-rays emitted is plotted against atomic number "Z", following graph is obtained. The value of 'n' is : Includes diagram2023 · 24 Jan · Shift 1 · Q12 · MCQ
  61. If wavelength of the first line of the Paschen series of hydrogen atom is 720 nm, then the wavelength of the second line of this series is ​ nm. (Nearest integer)2023 · 24 Jan · Shift 1 · Q23 · Numerical
  62. The magnetic moment of a transition metal compound has been calculated to be 3.87 B.M. The metal ion is2023 · 24 Jan · Shift 1 · Q8 · MCQ
  63. The number of s-electrons present in an ion with 55 protons in its unipositive state is2023 · 24 Jan · Shift 2 · Q1 · MCQ
  64. The radius of the 2nd orbit of Li2+ is x. The expected radius of the 3rd orbit of Be3+ is2023 · 25 Jan · Shift 1 · Q9 · MCQ
  65. The number of given orbitals which have electron density along the axis is ​ px​,py​,pz​,dxy​,dyz​,dxz​,dz2​,dx2−y2​2023 · 25 Jan · Shift 2 · Q18 · Numerical
  66. The shortest wavelength of hydrogen atom in Lyman series is λ. The longest wavelength is Balmer series of He + is2023 · 29 Jan · Shift 1 · Q7 · MCQ
  67. Assume that the radius of the first Bohr orbit of hydrogen atom is 0.6 Ao​. The radius of the third Bohr orbit of He + is ​ picometer. (Nearest Integer)2023 · 29 Jan · Shift 2 · Q22 · Numerical
  68. The energy of one mole of photons of radiation of frequency 2×1012 Hz in J mol−1 is ​. (Nearest integer) [Given : h=6.626×10−34 Js NA​=6.022×1023 mol−1…2023 · 30 Jan · Shift 1 · Q22 · Numerical
  69. Maximum number of electrons that can be accommodated in shell with n=4 are:2023 · 30 Jan · Shift 2 · Q10 · MCQ
  70. The wave function (Ψ) of 2 s is given by Ψ2 s​=22π​1​(a0​1​)1/2(2−a0​r​)e−r/2a0​ At r=r0​, radial node is formed. Thus, r0​ in…2023 · 30 Jan · Shift 2 · Q14 · MCQ
  71. Which transition in the hydrogen spectrum would have the same wavelength as the Balmer type transition from n=4 to n=2 of He+ spectrum2023 · 31 Jan · Shift 1 · Q11 · MCQ
  72. 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=3,l=1, m=0 D. n=3,l=2, m=1…2023 · 31 Jan · Shift 2 · Q7 · MCQ
  73. Consider the following pairs of electrons (A) (a) n = 3, l= 1, m1 = 1, ms = +21​(b) n = 3, 1 = 2, m1 = 1, ms = +21​(B) (a) n = 3, l= 2, m1 =− 2, ms = −21​(b) n = 3, l= 2, m1 =− 1, ms = $-{1 \over…2022 · 24 Jun · Shift 1 · Q2 · MCQ
  74. The energy of one mole of photons of radiation of wavelength 300 nm is (Given : h = 6.63 × 10 − 34 J s, NA = 6.02 × 1023 mol − 1, c = 3 × 108 m s − 1)2022 · 24 Jun · Shift 2 · Q2 · MCQ
  75. Which of the following sets of quantum numbers is not allowed?2022 · 25 Jul · Shift 1 · Q2 · MCQ
  76. When the excited electron of a H atom from n = 5 drops to the ground state, the maximum number of emission lines observed are ​.2022 · 25 Jul · Shift 2 · Q15 · Numerical
  77. The longest wavelength of light that can be used for the ionisation of lithium atom (Li) in its ground state is x × 10 − 8 m. The value of x is ​. (Nearest Integer). (Given : Energy of the electron in the…2022 · 25 Jun · Shift 1 · Q16 · Numerical
  78. The pair, in which ions are isoelectronic with Al3+ is :2022 · 25 Jun · Shift 1 · Q2 · MCQ
  79. The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is : [Given : The threshold frequency of platinum is 1.3 × 1015 s − 1 and h = 6.6 × 10 − 34 J s.]2022 · 25 Jun · Shift 2 · Q1 · MCQ
  80. The wavelength of an electron and a neutron will become equal when the velocity of the electron is x times the velocity of neutron. The value of x is ​. (Nearest Integer) (Mass of electron is 9.1×10−31 kg…2022 · 26 Jul · Shift 1 · Q17 · Numerical
  81. Consider an imaginary ion 2248​X3−. The nucleus contains 'a'% more neutrons than the number of electrons in the ion. The value of 'a' is ​. [nearest integer]2022 · 26 Jul · Shift 2 · Q13 · Numerical
  82. If the radius of the 3rd Bohr's orbit of hydrogen atom is r3 and the radius of 4th Bohr's orbit is r4. Then :2022 · 26 Jun · Shift 1 · Q2 · MCQ
  83. The number of radial and angular nodes in 4d orbital are, respectively2022 · 26 Jun · Shift 2 · Q1 · MCQ
  84. Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Energy of 2s orbital of hydrogen atom is greater than that of 2s orbital of lithium. Reason R:…2022 · 27 Jul · Shift 1 · Q3 · MCQ
  85. The correct decreasing order of energy for the orbitals having, following set of quantum numbers : (A) n = 3, l = 0, m = 0 (B) n = 4, l = 0, m = 0 (C) n = 3, l = 1, m = 0 (D) n = 3, l = 2, m = 1 is :2022 · 27 Jul · Shift 2 · Q1 · MCQ
  86. Outermost electronic configurations of four elements A, B, C, D are given below : (A) 3s2(B) 3s23p1(C) 3s23p3(D) 3s23p4 The correct order of first ionization enthalpy for them is :2022 · 27 Jul · Shift 2 · Q5 · MCQ
  87. If the uncertainty in velocity and position of a minute particle in space are, 2.4 × 10 − 26 (m s − 1) and 10 − 7 (m) respectively. The mass of the particle in g is ​. (Nearest integer) (Given : h =…2022 · 27 Jun · Shift 1 · Q11 · Numerical
  88. Consider the following set of quantum numbers. The number of correct sets of quantum numbers is ​. Includes table2022 · 27 Jun · Shift 2 · Q16 · Numerical
  89. Identify the incorrect statement from the following.2022 · 28 Jul · Shift 1 · Q1 · MCQ
  90. Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R Assertion A: Zero orbital overlap is an out of phase overlap. Reason R : It results due to…2022 · 28 Jul · Shift 2 · Q1 · MCQ
  91. If the wavelength for an electron emitted from H-atom is 3.3×10−10 m, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is ​…2022 · 28 Jul · Shift 2 · Q15 · Numerical
  92. If the work function of a metal is 6.63 × 10 − 19J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ​ nm. (Nearest integer) [Given : h = 6.63 × 10 − 34 J…2022 · 28 Jun · Shift 1 · Q15 · Numerical
  93. Consider the following statements : (A) The principal quantum number 'n' is a positive integer with values of 'n' = 1, 2, 3, ... (B) The azimuthal quantum number 'l' for a given 'n' (principal quantum number) can have values as 'l' = 0, 1,…2022 · 28 Jun · Shift 2 · Q2 · MCQ
  94. The minimum uncertainty in the speed of an electron in an one dimensional region of length 2ao​(Where ao​= Bohr radius 52.9pm) is ​kms−1…2022 · 29 Jul · Shift 1 · Q17 · Numerical
  95. Given below are the quantum numbers for 4 electrons. A. n=3,l=2, m1​=1, ms​=+1/2 B. n=4,l=1, m1​=0, ms​=+1/2 C. n=4,l=2, m1​=−2, ms​=−1/2…2022 · 29 Jul · Shift 2 · Q2 · MCQ
  96. Which of the following statements are correct? (A) The electronic configuration of Cr is [Ar] 3d5 4s1. (B) The magnetic quantum number may have a negative value. (C) In the ground state of an atom, the orbitals are filled in order of their…2022 · 29 Jun · Shift 1 · Q2 · MCQ
  97. Which of the following is the correct plot for the probability density ψ2 (r) as a function of distance 'r' of the electron from the nucleus for 2s orbital?2022 · 29 Jun · Shift 2 · Q1 · MCQ
  98. The number of radial nodes and total number of nodes in 4p orbital respectively are :2022 · 30 Jun · Shift 1 · Q1 · MCQ
  99. A 50 watt bulb emits monochromatic red light of wavelength of 795 nm. The number of photons emitted per second by the bulb is x × 1020. The value of x is ​. [Given : h = 6.63 × 10 − 34 Js and c =…2021 · 1 Sep · Shift 2 · Q20 · Numerical
  100. When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV, the de-Broglie wavelength of emitted electrons is ​Ao​. (Round off to the Nearest Integer). [ Use : 3​= 1.73, h =…2021 · 16 Mar · Shift 1 · Q21 · Numerical
  101. The number of orbitals with n = 5, m1 = +2 is ​. (Round off to the Nearest Integer).2021 · 16 Mar · Shift 2 · Q18 · Numerical
  102. A certain orbital has n = 4 and mL = − 3. The number of radial nodes in this orbital is ​. (Round off to the Nearest Integer).2021 · 17 Mar · Shift 1 · Q15 · Numerical
  103. A certain orbital has no angular nodes and two radial nodes. The orbital is :2021 · 18 Mar · Shift 1 · Q11 · MCQ
  104. Given below are two statements : Statement I : Bohr's theory accounts for the stability and line spectrum of Li+ ion. Statement II : Bohr's theory was unable to explain the splitting of spectral lines in the presence of a magnetic…2021 · 18 Mar · Shift 2 · Q9 · MCQ
  105. The Azimuthal quantum number for the valence electrons of Ga+ ion is ​. (Atomic number of Ga = 31)2021 · 20 Jul · Shift 1 · Q14 · Numerical
  106. The wavelength of electrons accelerated from rest through a potential difference of 40 kV is x × 10 − 12 m. The value of x is ​. (Nearest integer) Give : Mass of electron = 9.1 × 10 − 31 kg Charge…2021 · 20 Jul · Shift 2 · Q18 · Numerical
  107. Outermost electronic configuration of a group 13 element, E, is 4s2, 4p1. The electronic configuration of an element of p-block period-five placed diagonally to element, E is :2021 · 20 Jul · Shift 2 · Q5 · MCQ
  108. A proton and a Li3+ nucleus are accelerated by the same potential. If λLi​ and λp​ denote the de Broglie wavelengths of Li3+ and proton respectively, then the value of ${{{\lambda _{Li}}} \over {{\lambda…2021 · 24 Feb · Shift 1 · Q16 · Numerical
  109. According to Bohr's atomic theory : (A) Kinetic energy of electron is ∝n2Z2​. (B) The product of velocity (v) of electron and principal quantum number (n), ′vn′∝Z2. (C) Frequency of revolution of…2021 · 24 Feb · Shift 2 · Q4 · MCQ
  110. The plots of radial distribution functions for various orbitals of hydrogen atom against 'r' are given below : The correct plot for 3s orbital is : Includes diagram2021 · 25 Feb · Shift 1 · Q3 · MCQ
  111. Electromagnetic radiation of wavelength 663 nm is just sufficient to ionise the atom of metal A. The ionization enegy of metal A in kJ mol − 1 is ​. (Rounded off to the nearest integer) [h = 6.63 × 10 −…2021 · 25 Feb · Shift 2 · Q18 · Numerical
  112. Among the following, number of metal/s which can be used as electrodes in the photoelectric cell is ​. (Integer answer) (A) Li (B) Na (C) Rb (D) Cs2021 · 25 Feb · Shift 2 · Q23 · Numerical
  113. A source of monochromatic radiation of wavelength 400 nm provides 1000 J of energy in 10 seconds. When this radiation falls on the surface of sodium, x × 1020 electrons are ejected per second. Assume that wavelength 400 nm is…2021 · 25 Jul · Shift 1 · Q17 · Numerical
  114. An accelerated electron has a speed of 5 × 106 ms − 1 with an uncertainty of 0.02%. The uncertainty in finding its location while in motion is x × 10 − 9 m. The value of x is ​. (Nearest integer)…2021 · 25 Jul · Shift 2 · Q17 · Numerical
  115. Given below are two statements. Statement I : According to Bohr's model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron…2021 · 26 Aug · Shift 1 · Q10 · MCQ
  116. A metal surface is exposed to 500 nm radiation. The threshold frequency of the metal for photoelectric current is 4.3 × 1014 Hz. The velocity of ejected electron is ​× 105 ms − 1 (Nearest integer)…2021 · 26 Aug · Shift 2 · Q16 · Numerical
  117. The orbital having two radial as well as two angular nodes is :2021 · 26 Feb · Shift 1 · Q15 · MCQ
  118. A ball weighing 10 g is moving with a velocity of 90 ms − 1. If the uncertainty in its velocity is 5%, then the uncertainty in its position is ​× 10 − 33 m. (Rounded off to the nearest integer) [Given : h…2021 · 26 Feb · Shift 2 · Q24 · Numerical
  119. Which of the following forms of hydrogen emits low energy β- particles?2021 · 26 Feb · Shift 2 · Q6 · MCQ
  120. The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to xma02​h2​. The value of 10x is ​. (a0 is radius of Bohr's orbit) (Nearest integer) [Given : π = 3.14]2021 · 27 Aug · Shift 1 · Q15 · Numerical
  121. The number of photons emitted by a monochromatic (single frequency) infrared range finder of power 1 mW and wavelength of 1000 nm, in 0.1 second is x × 1013. The value of x is ​. (Nearest integer) (h = 6.63 ×…2021 · 27 Aug · Shift 2 · Q19 · Numerical
  122. Ge(Z = 32) in its ground state electronic configuration has x completely filled orbitals with ml = 0. The value of x is ​.2021 · 31 Aug · Shift 1 · Q20 · Numerical
  123. The figure that is not a direct manifestation of the quantum nature of atoms is :2020 · 2 Sep · Shift 1 · Q16 · MCQ
  124. The number of subshells associated with n = 4 and m = –2 quantum numbers is2020 · 2 Sep · Shift 2 · Q18 · MCQ
  125. The work function of sodium metal is 4.41 × 10–19 J. If photons of wavelength 300 nm are incident on the metal, the kinetic energy of the ejected electrons will be (h = 6.63 × 10–34 J s; c = 3 × 108 m/s) ​…2020 · 2 Sep · Shift 2 · Q3 · Numerical
  126. Consider the hypothetical situation where the azimuthal quantum number, l, takes values 0, 1, 2, ....., n + 1, where n is the principal quantum number. Then, the element with atomic number :2020 · 3 Sep · Shift 2 · Q14 · MCQ
  127. The region in the electromagnetic spectrum where the Balmar series lines appear is :2020 · 4 Sep · Shift 1 · Q18 · MCQ
  128. The shortest wavelength of H atom in the Lyman series is λ 1. The longest wavelength in the Balmar series of He+ is :2020 · 4 Sep · Shift 2 · Q19 · MCQ
  129. The difference between the radii of 3rd and 4th orbits of Li2+ is R1 . The difference between the radii of 3rd and 4th orbits of He+ is Δ R2 . Ratio Δ R1 : Δ R2 is :2020 · 5 Sep · Shift 1 · Q4 · MCQ
  130. The correct statement about probability density (except at infinite distance from nucleus) is :2020 · 5 Sep · Shift 2 · Q16 · MCQ
  131. The number of orbitals associated with quantum number n = 5, ms = +21​ is :2020 · 7 Jan · Shift 1 · Q5 · MCQ
  132. For the Balmer series in the spectrum of H atom, u=RH​{n12​1​−n22​1​}, the correct statements among (I) to (IV) are : (I) As wavelength decreases, the lines in the series converge…2020 · 8 Jan · Shift 1 · Q6 · MCQ
  133. Hydrogen has three isotopes (A), (B) and (C). If the number of neutron(s) in (A), (B) and (C) respectively, are (x), (y) and (z), the sum of (x), (y) an (z) is :2020 · 8 Jan · Shift 2 · Q12 · MCQ
  134. The radius of the second Bohr orbit, in terms of the Bohr radius, a0, in Li2+ is :2020 · 8 Jan · Shift 2 · Q16 · MCQ
  135. The de Broglie wavelength of an electron in the 4th Bohr orbit is :2020 · 9 Jan · Shift 1 · Q15 · MCQ
  136. The quantum number of four electrons are given below : n = 4, l = 2, ml =–2, ms = –1/2 n = 3, l = 2, ml = 1, ms = +1/2 n = 4, l = 1, ml = 0, ms = +1/2 n = 3, l = 1, ml = 1, ms = –1/2 The correct order of their increasing enegies will be :2019 · 8 Apr · Shift 1 · Q12 · MCQ
  137. If p is the momentum of the fastest electron ejected from a metal surface after the irradiation of light having wavelength λ, then for 1.5 p momentum of the photoelectron, the wavelength of the light should be: (Assume kinetic…2019 · 8 Apr · Shift 2 · Q3 · MCQ
  138. For any given series of spectral lines of atomic hydrogen, let Δv_= Δvmax​−Δvmin​ be the difference in maximum and minimum frequencies in cm–1. The ratio Lyman…2019 · 9 Apr · Shift 1 · Q19 · MCQ
  139. Which one of the following about an electron occupying the 1s orbital in a hydrogen atom is incorrect ? (The Bohr radius is represented by a0)2019 · 9 Apr · Shift 2 · Q14 · MCQ
  140. For emission line of atomic hydrogen from ni = 8 to nf = n, the plot of wave number (v) against (n21​) will be (The Rydberg constant, RH is in wave number unit)2019 · 9 Jan · Shift 1 · Q15 · MCQ
  141. The highest value of the calculated spin only magnetic moment (in BM) among all the transition metal complexes is :2019 · 9 Jan · Shift 1 · Q21 · MCQ
  142. Which of the following combination of statements is true regarding the interpretation of the atomic orbitals ? (a) An electron in an orbital of high angular momentum stays away from the nucleus than an electron in the orbital of lower…2019 · 9 Jan · Shift 2 · Q16 · MCQ
  143. The isoelectronic set of ions is :2019 · 10 Apr · Shift 1 · Q18 · MCQ
  144. The graph between ∣ψ∣2 and r (radial distance) is shown below. This represents : Includes diagram2019 · 10 Apr · Shift 1 · Q3 · MCQ
  145. The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series are :2019 · 10 Apr · Shift 2 · Q12 · MCQ
  146. Which of the graphs shown below does not represent the relationship between incident light and the electron ejected from metal surface ?2019 · 10 Jan · Shift 1 · Q9 · MCQ
  147. The ground state energy of hydrogen atom is – 13.6 eV. The energy of second excited state of He+ ion in eV is :2019 · 10 Jan · Shift 2 · Q20 · MCQ
  148. Heat treatment of muscular pain involves radiation of wavelength of about 900 nm. Which spectral line of H atom is suitable for this purpose? [RH = 1 × 105 cm–1, h = 6.6 × 10–34 Js, c = 3 × 108 ms–1]2019 · 11 Jan · Shift 1 · Q7 · MCQ
  149. The de Broglie wavelength (λ) associated with a photoelectron varies with the frequency (v) of the incident radiation as, [v0 is threshold frequency] :2019 · 11 Jan · Shift 2 · Q18 · MCQ
  150. The electrons are more likely to be found : Includes diagram2019 · 12 Apr · Shift 1 · Q15 · MCQ
  151. The group number, number of valence electrons, and valency of an element with atomic number 15, respectively, are:2019 · 12 Apr · Shift 1 · Q7 · MCQ
  152. What is the work function of the metal if the light of wavelength 4000 A∘​ generates photoelectrons of velocity 6 × 105 ms–1 from it ? (Mass of electron = 9 × 10–31 kg; Velocity of light = 3 × 108…2019 · 12 Jan · Shift 1 · Q19 · MCQ
  153. The upper stratosphere consisting of the ozone layer protects us from sun's radiation that falls in the wavelength region of -2019 · 12 Jan · Shift 2 · Q13 · MCQ
  154. If the de Broglie wavelength of the electron in nth Bohr orbit in a hydrogenic atom is equal to 1.5 π a0 (a0 is Bohr radius), then the value of n/z is -2019 · 12 Jan · Shift 2 · Q15 · MCQ
  155. Ejection of the photoelectron from metal in the photoelectric experiment can be stopped by applying 0.5 V when the radiation of 250 nm is used. The work function of the metal is :2018 · 15 Apr · Shift 1 · Q21 · MCQ
  156. The de-Broglie's wavelength of electron present in first Bohr orbit of 'H' atom is :2018 · 15 Apr · Shift 2 · Q21 · MCQ
  157. Which of the following statements is false ?2018 · 16 Apr · Shift 1 · Q24 · MCQ
  158. If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of He+ is :2017 · 8 Apr · Shift 1 · Q22 · MCQ
  159. The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with :2017 · 9 Apr · Shift 1 · Q21 · MCQ
  160. The group having isoelectronic species is:2017 · Shift 0 · Q20 · MCQ
  161. The radius of the second Bohr orbit for hydrogen atom is: (Planck’s Const. h = 6.6262 × 10-34 Js; mass of electron = 9.1091 × 10-31 kg; charge of electron (e) = 1.60210 × 10-19 C; permittivity of vacuum ({varepsilon _0}) = 8.854185 ×…2017 · Shift 0 · Q23 · MCQ
  162. The total number of orbitals associated with the principal quantum number 5 is :2016 · 9 Apr · Shift 1 · Q18 · MCQ
  163. A stream of electrons from a heated filament was passed between two charged plates kept at a potential difference V esu. If e and m are charge and mass of an electron, respectively, then the value of h / λ(where λ is…2016 · Shift 0 · Q18 · MCQ
  164. Which of the following is the energy of a possible excited state of hydrogen?2015 · Shift 0 · Q22 · MCQ
  165. The correct set of four quantum numbers for the valence elections of rubidium atom (Z= 37) is:2014 · Shift 0 · Q24 · MCQ
  166. Energy of an electron is given by E=−2.178×10−18J(n2Z2​). Wavelength of light required to excite an electron in an hydrogen atom from level n = 1 to n = 2 will be (h = 6.62 × 10−34 Js…2013 · Shift 0 · Q23 · MCQ
  167. The electrons identified by quantum numbers n and l : (a) n = 4, l= 1 (b) n = 4, l= 0 (c) n = 3, l= 2 (d) n = 3, l = 1 Can be placed in order of increasing energy as :2012 · Shift 0 · Q22 · MCQ
  168. A gas absorbs a photon of 355 nm and emits at two wavelengths. If one of the emissions is at 680 nm, the other is at :2011 · Shift 0 · Q28 · MCQ
  169. Ionisation energy of He+ is 19.6 x 10–18 J atom–1. The energy of the first stationary state (n = 1) of Li2+ is2010 · Shift 0 · Q25 · MCQ
  170. The energy required to break one mole of Cl–Cl bonds in Cl2​ is 242 kJ mol–1. The longest wavelength of light capable of breaking a single Cl – Cl bond is (c = 3 x 108 ms–1 and NA = 6.02 x 1023 mol–1)2010 · Shift 0 · Q26 · MCQ
  171. In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainity with which the position of the electron can be located is (h = 6.6 × 10-34 kg m2s-1, mass of electron, em = 9.1 × 10-31 kg)2009 · Shift 0 · Q24 · MCQ
  172. Calculate the wavelength (in nanometer) associated with a proton moving at 1.0 x 103 ms−1 (Mass of proton = 1.67 × 10-27 kg and h = 6.63 × 10-34 Js) :2009 · Shift 0 · Q25 · MCQ
  173. The ionization enthalpy of hydrogen atom is 1.312 × 106 J mol−1. The energy required to excite the electron in the atom from n = 1 to n = 2 is2008 · Shift 0 · Q28 · MCQ
  174. Which one of the following constitutes a group of the isoelectronic species?2008 · Shift 0 · Q29 · MCQ
  175. Which of the following sets of quantum numbers represents the highest energy of an atom?2007 · Shift 0 · Q36 · MCQ
  176. Uncertainty in the position of an electron (mass = 9.1 × 10-31 kg) moving with a velocity 300 ms-1, accurate upto 0.001% will be (h = 6.63 × 10-34 Js)2006 · Shift 0 · Q45 · MCQ
  177. According to Bohr's theory, the angular momentum of an electron in 5th orbit is2006 · Shift 0 · Q46 · MCQ
  178. Which of the following sets of ions represents a collection of isoelectronic species?2006 · Shift 0 · Q47 · MCQ
  179. Pick out the isoelectronic structure from the following : ​(i)CH3​+(ii)H3​O+(iii)NH3​(iv)CH3​−​…2005 · Shift 0 · Q32 · MCQ
  180. Of the following sets which one does NOT contain isoelectronic species?2005 · Shift 0 · Q55 · MCQ
  181. In a multi-electron atom, which of the following orbitals described by the three quantum members will have the same energy in the absence of magnetic and electric fields? (A) n = 1, l = 0, m = 0 (B) n = 2, l = 0, m = 0 (C) n = 2, l = 1, m…2005 · Shift 0 · Q56 · MCQ
  182. Which of the following sets of quantum numbers is correct for an electron in 4f orbital?2004 · Shift 0 · Q55 · MCQ
  183. Consider the ground state of Cr atom (Z = 24). The number of electrons with the azimuthal quantum numbers, l = 1 and 2 are respectively2004 · Shift 0 · Q56 · MCQ
  184. The wavelength of the radiation emitted when in a hydrogen atom electron falls from infinity to stationary state 1, would be (Rydberg constant = 1.097 × 107 m-1)2004 · Shift 0 · Q57 · MCQ
  185. Which one of the following sets of ions represents the collection of isoelectronic species? (Atomic nos. : F = 9, Cl = 17, Na = 11, Mg = 12, Al = 13, K = 19, Ca = 20, Sc = 21)2004 · Shift 0 · Q58 · MCQ
  186. The orbital angular momentum for an electron revolving in an orbit is given by l(l+1)​2πh​. This momentum for an s-electron will be given by2003 · Shift 0 · Q56 · MCQ
  187. Which one of the following groupings represents a collection of isoelectronic species? (At. nos. : Cs : 55, Br : 35)2003 · Shift 0 · Q57 · MCQ
  188. In Bohr series of lines of hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen2003 · Shift 0 · Q58 · MCQ
  189. The de Broglie wavelength of a tennis ball of mass 60 g moving with a velocity of 10 meters per second is approximately2003 · Shift 0 · Q59 · MCQ
  190. Uncertainty in position of a minute particle of mass 25 g in space is 10-5 m. What is the uncertainty in its velocity (in ms-1) (h = 6.6 × 10-34 Js)2002 · Shift 0 · Q55 · MCQ
  191. In a hydrogen atom, if energy of an electron in ground state is -13.6 eV, then that in the 2nd excited state is2002 · Shift 0 · Q56 · MCQ