Students of class 11 Chemistry should refer to MCQ Questions Class 11 Chemistry Structure of Atom with answers provided here which is an important chapter in Class 11 Chemistry NCERT textbook. These MCQ for Class 11 Chemistry with Answers have been prepared based on the latest CBSE and NCERT syllabus and examination guidelines for Class 11 Chemistry. The following MCQs can help you to practice and get better marks in the upcoming class 11 Chemistry examination

Chapter 2 Structure of Atom MCQ with Answers Class 11 Chemistry

MCQ Questions Class 11 Chemistry Structure of Atom provided below have been prepared by expert teachers of grade 11. These objective questions with solutions are expected to come in the upcoming Standard 11 examinations. Learn the below provided MCQ questions to get better marks in examinations.

Question. The total mass of neutrons in 7 mg of C¹⁴ (assume mass of a neutron = × − 1.675 10⁻²⁷. kg) is
(a) 1.25 × 10^{− 9}
(b) 2.40 × 10⁻⁸
(c) 4.03 × 10⁻⁶
(d) 5.36 × 10⁻⁷

Question. The frequency of light emitted for the transition n = 4 to n = 2 of He⁺ is equal to the transition in H atom corresponding to which of the following?
(a) n = 3 to n = 1
(b) n = 2 to n = 1
(c) n = 3 to n = 2
(d) n = 4 to n = 3

Question. Rutherford’s a-particle scattering experiment eventually concluded that
(a) mass and energy are related
(b) neutrons are buried deep in the nucleus
(c) electrons occupy space around the nucleus
(d) the point of impactwithmatter can be precisely determined

Question. A photon of light of wavelength 6000 Å has energy E. What will be the wavelength of photon of a ight which has energy of photon 4E ?
(a) 1500 Å
(b) 6000 Å
(c) 2000 Å
(d) 750 Å

Question. A 25 Watt bulb emits monochromatic yellow light of wavelength of 0.57 μm. What will be the rate of  mission of quanta per second?
(a) 7.17   × 10¹⁹ .
(b) 0.717 × 10⁻¹⁹
(c) 71.7   × 10¹⁹ 
(d) 7.17   × 10⁻¹⁹

Question. The critical wavelength for producing the photoelectric effect in tungsten metal is 2600 Å. What  avelength would be necessary to produce photoelectrons from tungsten having twice the kinetic energy  f those produced at 2200 Å?
(a) 1800 Å
(b) 1907 Å
(c) 1926 Å
(d) 2015 Å

Question. To move an electron in one H-atom from the ground state to the second excited state, 12.084 eV are needed. How much energy is needed to cause 1 mole of H-atoms to undergo this transition ?
(a) 728 kJ/mol
(b) 984 kJ/mol
(c) 1036 kJ/mol
(d) 1164 kJ/mol

Question. Many elements have non-integral atomic masses because
(a) their isotopes have same number of neutrons
(b) their isotopes have non-integral masses
(c) they exist as isotopes
(d) their constituents neutrons, protons and electrons combine to give fractional masses

Question. Energy required to stop the ejection of electrons from Cu plate is 0.24 eV. If radiation of l = 253.7  m strikes the plate, the work function is
(a) 4.65 eV
(b) 4.89 eV
(c) 4.24 eV
(d) 3.0 eV

Question. Which hydrogen like species will have same radius as that of Bohr orbit of hydrogen atom ?
(a) n = 2 , Li²⁺
(b) n = 2 , Be³⁺
(c) n = 2 , He⁺
(d) n = 3 , Li²⁺

Question. The atomic numbers of elements x, y and z are 19, 21 and 25 respectively. The number of electrons present in M-shell of these elements follow the order
(a) z > x > y
(b) x > y > z
(c) z > y > x
(d) y > z > x

Question. I₂ molecule dissociates into atoms after absorbing light of 4500 Å. If one quantum of energy is absorbed by each molecule, the KE of iodine atoms will be
(BE of I₂ = 240 kJ / mol) 
(a) 240    × 10¯19 J
(b) 0.216 × 10⁻¹⁹ J
(c) 2.16   × 10⁻¹⁹ J
(d) 2.40   × 10⁻¹⁹ J

Question. In Bohr’s series of lines of hydrogen spectrum, the third line from the red end corresponds to which  ne of the following inter-orbit jumps of the electron for Bohr’s orbit in an atom of hydrogen?
(a) 5 → 2
(b) 4 → 1
(c) 2 → 5
(d) 3 → 2

Question. In a multielectron atom, which of the following orbitals described by the three quantum numbers wil 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 =1
(D) n = 3, l = 2,m =1
(E) n = 3, l = 2,m = 0
(a) (D) and (E)
(b) (C) and (D)
(c) (B) and (C)
(d) (A) and (B)

Question. Consider the following sets of quantum numbers.
n        l     m         s
I.3     0     0        +1/2
II.2    2     1        +1/2
III.4   3     −2     −1/2
IV.1    0     −1     −1/2
V.2     3     3        +1/2
Which of the following sets of the quantum number is not possible?
(a) II, III and IV
(b) I, II, III and IV
(c) II, IV and V
(d) I and III

Question. When the electron of a hydrogen atom jumps, from the n = 4 to the n =1 state, the number of  pectral lines emitted is
(a) 15
(b) 6
(c) 3
(d) 4

Question. If the speed of an electron in the Bohr’s first orbit of hydrogen atom be x, speed of the electron in 3^rd orbit is
(a) x /9
(b) x /3
(c) 3x
(d) 9x

Question. The ionisation enthalpy of hydrogen atom is 1.312 10 Jmol × 6 −1. The energy require to excite the electrons in an atom from n =1 to n = 2 is
(a) 7.56 10× 5 J mol−1
(b) 9.84 10× 5 J mol−1
(c) 8.51 10× 5 J mol−1
(d) 6.56 10× 5 J mol−1

Question. Amongst the following set of quantum numbers, the impossible set is
     n   l      m       s                         
(a) 3   2   −3     1/2
(b) 4   0     0     1/2
(c) 5   3     0   −1/2
(d) 3   2   −2     1/2

Question. The wave number of first line of Balmer series of hydrogen is 15200 cm ⁻¹. The wave number of  irst Balmer line of Li²⁺ ion is
(a) 15200 cm ⁻¹
(b) 60800 cm ⁻¹
(c) 76000 cm ⁻¹
(d) 136800 cm ⁻¹

Question. The wave number of the first emission line in the Balmer series of H-spectrum is (R = Rydberg  onstant)
(a) 5/36 R
(b) 9/400 R
(c) 7/6 R
(d) 3/4 

Question. The correct set of four quantum numbers for the valence electrons of rubidium atom(Z = 37) is 
(a) 5.0.0.+1/2
(b) 5.1.0.+1/2 
(c) 5.1.1.+1/2
(d) 5.0.1.+1/2

Question. The energy required to break one mole of Cl—Cl bonds inCl2 is 242 kJ mol⁻¹. The longest avelength of light capable of breaking a single Cl—Cl bond is
(a) 594 nm
(b) 640 nm
(c) 700 nm
(d) 494 nm

Question. When an electron is excited from ground level to 5th orbit, the number of spectral lines obtained in Bohr spectrum of H-atom is
(a) 5
(b) 8
(c) 10
(d) 15

Question. Which of the following is the energy of a possible excited state of hydrogen? 
(a) +13.6 eV
(b) − 6.8eV
(c) −3.4eV
(d) + 6.8eV

Question. The de-Broglie wavelength of a car of mass 1000 kg and velocity 36 km/h is (h = 6.63 ×10⁻³⁴ Js) 
(a) 6.626 × 10⁻³⁴ m 
(b) 6.626 × 10⁻³⁸ m
(c) 6.626 × 10⁻³¹ m 
(d) 6.626 × 10⁻³⁰ m 

Question. A stream of electrons from a heated filament was passed between two charged plates kept at a  otential difference V esu. If e andm are charge and mass of an electron, respectively, then the value of  /l (where, l is wavelength associated with electron wave) is given by 
(a) 2 meV
(b)√ meV
(c) √2meV
(d) meV

Question. The uncertainty in the position of an electron moving with a velocity of 300 ms⁻¹ alongwith an  ccuracy of 0.001% is
(a) 3.84 × 10⁻² m
(b) 5.76 × 10⁻² m
(c) 1.93 × 10⁻² m
(d) 19.3 × 10⁻² m

Question. If the shortest wavelength of H-atom in Lyman series is X, the longest wavelength in Balmer series  fHe⁺ is
(a) 9X/5
(b) 36X/5
(c) X/4
(d) 5X/9

Question. In an atom how many orbital(s) will have the quantum numbers n =3, l = 2 andml = + 2 ? 
(a) 5
(b) 3
(c) 1
(d) 7

Question. A dust particle has mass equal to 10⁻¹¹ g  , diameter 10⁻⁴ cm and velocity10⁻⁴ cms⁻¹. The rror in measurement of velocity is 0.1%. What will be the uncertainty in its position ?
(a) 0.527 × 10⁻¹⁰ m
(b) 5.27   × 10⁻⁹   cm 
(c) 0.527 × 10⁻¹⁵ cm 
(d) 0.527 × 10⁻⁹  cm

Question. The uncertainty involved in the measurement of velocity of an electron within a distance of 0.1Å is
(a) 5.79 × 10⁸ ms⁻¹
(b) 5.79 × 10⁵ ms⁻¹
(c) 5.79 × 10⁶ ms⁻¹
(d) 5.79 × 10⁷ ms⁻¹

Question. How many times does the electron go round the first Bohr’s orbit of hydrogen in one second ?
(a) 0.657 × 10¹⁵
(b) 6.57 × 10¹⁵
(c) 6.57 × 10¹⁰
(d) 65.7 × 10¹²

Question. A photon of 300 nm is absorbed by a gas which thenre-emits two photons. One re-emitted photon has wavelength of 496 nm. Wavelength of other re-emitted photon is
(a) 300 nm
(b) 496 nm
(c) 759 nm
(d) 550 nm

Question.35 In an atom, an electron is moving with a speed of 600 m/s with an accuracy of 0.005%. Certainty with which the position of the electron can be located is
(h 6.6 × 10^–34 kg m²s⁻¹, mass of electron, e_m = 9.1 × 10⁻³¹kg
(a) 1.52 × 10⁻⁴ m
(b) 5.10 × 10⁻³ m
(c) 1. 92 × 10⁻³ m
(d) 3.84 × 10⁻³ m

Question. The radii of an atom and atomic nucleus is of the order of
(a) 10⁻¹² m and 10⁻¹⁰ m
(b) 10⁻¹⁰ cm and 10⁻⁸ cm
(c) 10⁻¹⁰ m and 10⁻¹⁵ m
(d) 10⁻¹⁵ m and 10⁻¹⁰ m

Question. Atom consists of electrons, protons and neutrons. If the mass attributed to neutron is halved and that  ttributed to the electrons is doubled, the atomic mass of 6 12 C would be approximately
(a) same
(b) doubled
(c) halved
(d) reduced by 25

Question. Which of the following is not possible for 4p or 3d electrons?
(a) n = 3, l = 2,m = +1, s = +1/2
(b) n = 4, l = 1,m = 0, s = +1/2
(c) n = 3, l = 3,m = +3, s = +1/2
(d) n = 4, l = 1,m = −1, s = +1/2

Question. In a Bohr’s model of atom when an electron in H-atom jumps from n =1 to n = 3, how much energy will be emitted or absorbed?
(a) 2.15   × 10⁻¹¹  erg/atom
(b) 1.936 × 10⁻¹¹ erg/atom
(c) 2.389 × 10⁻¹²  erg/atom
(d) 0.239 × 10⁻¹⁰  erg/atom

Question. Which of the following statements in relation to the hydrogen atom is correct?
(a) 3s, 3p and 3d orbitals all have the same energy
(b) 3s and 3p orbitals are of lower energy than 3d-orbital
(c) 3p-orbital is lower in energy than 3d-orbital
(d)3s-orbital is lower in energy than 3p-orbital

Question. The radiation is emitted when a hydrogen atom goes from a higher energy state to a lower energy state. The wavelength of one line in visible region of atomic spectrum of hydrogen is 6.63 10 m. × −7 Energy difference between the two states is
(a) 3.0 10 × 10⁻¹⁹ J
(b) 1.0 10 × 10⁻¹⁸ J
(c) 5.0 10 × 10⁻¹⁰ J
(d) 6.5 10 × 10⁻⁷ J

Question. Given the set of quantum numbers for a multi-electron atom 2, 0, 0,1/2 and 2, 0, 0, − 1/2. What is the next higher allowed set of n and l quantum numbers for this atom in its ground tate?
(a) n = 2, l = 0
(b) n = 2, l = 1
(c) n = 3, l = 0
(d) n = 3, l = 1

Question. Ionisation energy of He⁺ is 19.6 × 10⁻¹⁸ J atom⁻¹ The energy of the first stationary state (n = 1)of Li²⁺ is
(a) 4.41 × 10⁻¹⁶ J atom⁻¹
(b) −4.41 × 10⁻¹⁷ J atom ¹
(c) −2.2 × 10⁻¹⁵ J atom¹
(d) 8.82 × 10⁻¹⁷ J atom⁻¹

Question. The wavelength of a neutron with a translatory kinetic energy equal to kT at 300 K is
(a) 17.8 pm
(b) 20.0 pm
(c) 200 pm
(d) 178 pm

Question. A gas absorbs photon of 355 nm and emits at two wavelengths. If one of the emission is at 680 nm, the other
(a) 1035 nm
(b) 325 nm
(c) 743 nm
(d) 518 nm

Question. For the electrons of oxygen atom, which of the following statements is correct?
(a) Z_eff for an electron in a 2s-orbital is the same as Z_eff for an electron in a 2p-orbital
(b) An electron in the 2s-orbital has the same energy as an electron in the 2p-orbital
(c) Z_eff for an electron in 1s-orbital is the same as Z_eff for an electron in a 2s-orbital
(d) The two electrons present in the 2s-orbital have spin quantum numbers m_s but of opposite sign

Question. Which of the following statements about electromagnetic spectrum is not correct?
(a) Infrared radiations have larger wavelength than cosmic rays
(b) The frequency of microwaves is less than that of ultraviolet rays
(c) X-rays have larger wave number than microwaves
(d) The velocity of X-rays is more than that of microwaves

We hope the above multiple choice questions for Class 11 Chemistry for Chapter 2 Structure of Atom provided above with answers based on the latest syllabus and examination guidelines issued by CBSE, NCERT and KVS are really useful for you. Structure of Atom is an important chapter in Class 11 as it provides very strong understanding about this topic. Students should go through the answers provided for the MCQs after they have themselves solved the questions. All MCQs have been provided with four options for the students to solve. These questions are really useful for benefit of class 11 students. Please go through these and let us know if you have any feedback in the comments section.