Assignment_Sem1ch2
1. The Greek word ‘ tomio’ means
(a) atom
(b) particle
Ans (c)
(c) breakable
(d) unbreakable
2. Dalton’s atomic theory was able to explain
(a) Faraday’s laws (b) Lavoisier’s law (c) Einstein’s law (d) Von Helmholtz law
Ans (b)
3. Dalton’s atomic theory could not explain
(a) law of conservation of mass
(b) law of multiple proportion
(c) law of constant proportion
(d) laws of electricity
Ans (d)
4. The electrical discharge through the gases could be observed
(a) only at very low pressure
(b) only at very high voltage
(c) only at very low pressures and at very high voltages
(d) only at very high pressure and at very low voltages
Ans (c)
5. Who began to study electrical discharge in cathode ray discharge tube ?
(a) Faraday (b) Maxwell
(c) J.J. Thomson (d) Goldstein
Ans (a)
6. The charge on anode and cathode of cathode ray discharge tube are
respectively
(a) +ve and +ve
(b) +ve and –ve
(c) –ve and +ve
(d) –ve and neutral
Ans (b)
7. The current starts flowing through a stream of particles moving in the tube.
(a) from anode to cathode
(b) from –ve electrode to +ve electrode
(c) from cathode to vacuum pump
(d) none of the above
Ans (b)
8. The characteristic of cathode rays is
(a) invisible
(b) deviate towards –ve plate
(c) starts from anode
(d) visible
Ans (a)
9. The cathode rays are
(a) electrons
(b) protons
Ans (a)
(c) neutrons
(d) meson
10. The characteristic of cathode rays do not depend upon
(a) the magnetic field
(b) the electrical field
(c) materials of electrodes
(d) vacuum
Ans (c)
11. e/m ratio was discovered by
(a) Rutherford
(b) Einstein
Ans (d)
(c) Planck
(d) Thomson
12. How is magnitude of charge responsible for deflection in cathode ray tube
?
(a) smaller the magnitude – smaller is the deflection
(b) greater the magnitude – smaller is the deflection
(c) greater the magnitude – greater is the deflection
(d) smaller the magnitude – greater the deflection
Ans (c)
13. How is mass of particle responsible for deflection in cathode ray tube ?
(a) lighter the particle – greater is the deflection
(b) lighter the particle – smaller is the deflection
(c) heavier the particle – greater is the deflection
(d) heavier the particle – smaller is the deflection
Ans (a)
14. The value of e/m for electron is
(a) 1.758820 X 1012 C kg-1
(b) 1.758820 X 1010 C kg-1
(c) 1.758820 X 1011 C kg-1
(d) 1.758820 X 10-19 C kg-1
Ans (c)
15. Who determined the charge of electron ?
(a) Thomson
(b) Rutherford
(c) Millikan
Ans (c)
(d) Einstein
16. If e = 1.6022 X 10-19 coulomb and e/m = 1.758820 X 1011 C kg-1 , the mass of
electron would be
(a)1.673 X 10-27 kg (b)1.675 X 10-27 kg (c)9.109 X 10-28 kg (d)9.109 X 10-31 kg
Ans (d)
17. Positively charge particles are known as
(a) canaly rays
(b) cathode rays (c)  rays
Ans (a)
(d)  rays
18. Neutrons were discovered by Chadwick by bombarding
(a)  - particles on Zn sheet
(b)  - particles on Be sheet
(c)  - particles on Au sheet
(d)  - particles on Au sheet
Ans (b)
19. Thomson model of atom was not named as
(a) plum pudding (b) raisin pudding (c) water melon (d) sweet melon
Ans (d)
20. The atomic radius of Thomson model is
(a) approximately 10-10 m
(b) approximately 10-12 m
(c) approximately 10-14 m
(d) approximately 10-15 m
Ans (a)
21. Thomson was awarded Nobel prize for
(a) discovery of proton
(b) discovery of structure of atom
(c) investigations on the conduction of electricity by gases
(d) discovery of e/m ratio
Ans (c)
21.  - particle consists of
(a) two protons
(b) one proton
(c) one proton and one neutron
(d) two protons and two neutrons
Ans (d)
22.  - particle consists of
(a) electron
(c) neutron
Ans (a)
(b) one electron and one proton
(d) positron
23. Who discovered radioactivity ?
(a) Madame curie
(b) Henry Becqueral
(c) Thomson
(d) Rutherford
Ans (b)
24. Who discovered the charge of  and  rays ?
(a) M. Curie
(b) Henry becqueral
(c) Thomson
(d) Rutherford
Ans (d)
25. Who observed reflection of  particle from Au foil in  ray scattering
experiment is ?
(a) Rutherford
(b) Geiger
(c) Marsden
(d) Mathew
Ans (c)
26. The thickness of Au foil used in  ray scattering experiment is
(a) 100 cm
(b) 100 nm
(c) 10 nm
(d) 1 nm
Ans (b)
27. When  particles were bombarded on Au foil the following was not
observed
(a) most of the  particles passed through the gold foil undeflected
(b) a small fraction of the  particle was deflected by small angles
(c) very few  particles bounced back
(d) about 79  particles bounced back
Ans (d)
28. Most of the space in the atom is empty
(a) as most of the  particles passed through the foil undeflected
(b) as small fraction of  particles was deflected by small angles
(c) a very few  particles bounced back
(d) all of the above
Ans (a)
29. According to Rutherford model
(a) The positive charge and most of the mass of the atom was densely
concentrated in extremely small region
(b) The centre of atom is known as nucleus
(c) The electron move around the nucleus in circular path
(d) All of the above
Ans (d)
30. Nucleons are
(a) protons only
(b) neutrons only
(c) protons and neutrons only (d) proton, neutron and electrons
Ans (c)
31. No. of neutrons in 92U238 are
(a) 145
(b) 146
Ans (b)
(c) 147
32. The atomic mass number of radioactive C is
(a) 12
(b) 13
(c) 14
(d) 15
Ans (c)
(d) 148
33. The number of protons , neutrons and electrons in 35Br80 are
(a) 35,45,45
(b) 45,35,45
(c) 45,35,35
(d) 35,45,35
Ans (d)
34. The number of electrons , protons and neutrons in a species are equal to 7
, 7 and 7 respectively , the element must be
(a) N15
(b) N14
(c) C14
(d) O15
Ans (b)
35. Which one is the pair of isobars ?
(a) C12, C13
(b) N14, C14
(c) O15, O16
Ans (b)
(d) P31, S32
36. Which one is the pair of isotones ?
(a) C12, C13
(b) N14, C14
(c) O15, O16
Ans (d)
(d) P31, S32
37. Protium , deuterium and tritium are known as
(a) isotones
(b) isobars
(c) isotopes
Ans (c)
(d) all of the above
38. One of the drawback of the Rutherford’s model is
(a) electron continuously moving around nucleus
(b) every atom has a centre
(c) It cannot explain spectra of other than hydrogen
(d) It cannot explain the stability of an atom
Ans (d)
39. The frequency of violet (400 nm) colour is
(a) 7 X 1014 Hz
(b) 8.5 X 1014 Hz
(c) 7.5 X 1015 Hz
(d) 7.5 X 1014 Hz
Ans (d)
40. The frequency of red (750nm) colour is
(a) 4 X 1014 Hz
(b) 5 X 1015 Hz
(c) 3 X 1014 Hz
(d) 4 X 1015 Hz
Ans (a)
41. The wave number of yellow radiation having wavelength 5800Å is
(a) 7.24 X 104 cm-1 (b) 1.724 X 104 cm-1
(c) 1.924 X 104 cm-1
(d) 1.724 X 105 cm-1
Ans (b)
42. According to Max Planck the smallest quantity of energy that can be
emitted or absorbed in the form of electromagnetic radiation is known as
(a) photon (b) quantum
(c) black body
(d) none of the above
Ans (b)
43. The ideal black body is known as
(a) the body which only emits radiation
(b) the body which only absorbs radiation
(c) the body which emits and absorbs few frequencies
(d) the body which emits and absorbs all frequencies
Ans (d)
44. Max Planck ‘s quantum theory is
(a) the atoms or molecules could not emit (or absorb) energy continuously
(b) atoms or molecules could not emit (or absorb) energy only in discrete
quantities
(c) atoms or molecules could not emit after absorption of energy
(d) none
Ans (b)
45. The electrons were ejected when certain metals were exposed to a beam
of light, this experiment first of all in 1887 was performed by
(a) Einstein
(b) Becqueral
(c) Planck
(d) Hertz
Ans (d)
46. Which one is the statement explaining photoelectric effect ?
(a) the electrons are ejected from the metal surface as soon as the beam of
light strikes the surface.
(b) the number of electrons ejected is proportional to intensity of light.
(c) for each metal there is a characteristic minimum frequency o (threshold
frequency) below which photoelectric effect is not observed.
(d) all of above
Ans (d)
47. From which of the following it is proved that nucleus of atom contains
positive charge ?
(a) Thomson model of an atom
(b) Bohr’s atomic model
(c) De- broglie’s principle
(d) - particle scattering experiment
Ans (d)
48. Which of the following is the correct formula for one Einstein ?
(a) Nc/
(b) Nhc/
(c) hc/
(d) Nh/c
Ans (b)
49. Atomic mass can be known from which of the following equation?
(a) Z + n
(b) Z + e(c) N + e(d) none
Ans (a)
50. When a light passes through prism , the dispersion takes place in which
(a) the light of red colour which has longest wavelength is deviated the most
(b) the light of red colour which has longest wavelength is deviated the least
(c) the light of blue colour which has longest wavelength is deviated the most
(d) the light of blue colour which has shortest wavelength is deviated the least
Ans (b)
51. Define : spectroscopy
(a) the study of absorption spectra only
(b) the study of emission spectra only
(c) the study of absorption and emission spectra
(d) the study of absorption or emission spectra
Ans (d)
52. The other names of hydrogen spectra
(a) emission spectra
(b) atomic spectra
(c) line spectra
(d) all of above
Ans (d)
53. In formula  = R ( 1/m2 – 1/n2 ) R is known as
(a) Ritz constant
(b) Rydberg constant
(c) Robert constant
(d) Boltzmann constant
Ans (b)
54. In the formula  = R ( 1/m2 – 1/n2 ) R is known as
(a) Ritz constant
(b) Rydberg constant
(c) Robert constant
(d) Boltzman constant
Ans (a)
55. The spectrophotometer was first of all designed by
(a) R. Bunsen only
(b) Kirchoff only
(c) William Crook
(d) Kirchoff and Bunsen
Ans (d)
56. The first hydrogen spectra was taken by
(a) Lyman (b) Balmer (c) Brackett
(d) Paschen
Ans (b)
57. Atomic emission spectra is obtained when
(a) the light emitted as excited atoms fall to lower energy states
(b) the light absorbed and atoms from ground state transit to higher state
(c) molecule absorbed light and return to ground state
(d) all of above
Ans (a)
58. Atomic absorption spectra is infact
(a) the photographic positive of the emission spectrum
(b) the reverse image of the emission spectrum.
(c) the photographic negative of the emission spectrum
(d) none of the above
Ans (c)
59. Which elements were easily discovered by spectroscopic methods ?
(a) H , Li , Cs , Ga
(b) Rb , Cs , Tl , In , Ga , Sc , He
(c) Na , K , Rb , Cs
(d) Ge , Ga , Sc , Cu
Ans (b)
60. Which feature is common to all line spectra ?
(a) line spectrum of the element is not unique
(b) there is irregularity in the line spectrum of each element
(c) there is regularity in the line spectrum of each element
(d) all spectras are similar in case of wavelength of line.
Ans (c)
61. Who used quantum theory to explain structure of atom ?
(a) Thomson
(b) Planck
(c) Bohr
(d) Rutherford
Ans (c)
62. Calculate Bohr’s radius where r = n2a0 and a0 = 52.9 pm
(a) 106 pm
(b) 52.9 pm
(c) 52.9 nm
(d) 5.29 X 10-8 m
Ans (b)
63. The radius of 3rd orbit where r = n2a0 and a0 = 52.9 pm is ,
(a) 484 pm
(b) 476.1 nm
(c) 476.1 pm
(d) 401 pm
Ans (c)
64. If En = -RH (1/n2)J where RH = 2.18 X 10-18 J the energy of 1st orbit is
(a) -2.18 X 10-18 J (b) 2.18 X 10-18 J (c) -0.545 X 10-18 J (d) 8.74 X 10-18 J
Ans (a)
65. If En = -RH (1/n2) and RH = 2.18 X 10-18 J , the energy of the 2nd orbit will be
a. -2.18 X 10-18 J b. 2.18 X 10-18 J
c. 5.45 X 10-18 J
d. -5.45 X 10-19 J
Ans (d)
66. When the electron is free from the influence of nucleus, the energy is taken
as
a. Zero
b. positive
c. negative
d. Infinite
Ans (a)
67. Which are of the following is hydrogen like species ?
a. He
b. Li+
c. H+
Ans (d)
d. Be+3
68. If En = -2.18 X 10-18 (Z2/n2) J, the energy of He+ would be
a. -2.18 X 10-18
b. -2.19 X 10-18
c. -0.18 X 10-18
d. -8.72 X 10-18
Ans (d)
69. If En = -2.18 X 10-18 (Z2/n2) J, the energy of Li+2 would be
a. -2.19 X 10-18 b. -4.18 X 10-18 c.-19.62 10-18 d. -18.19 X 10-18
Ans (c)
70. If rn = 52.9(n2)/Z pm, the radius of He+ would be
a. 0.2645 nm
b. 2.645 nm
c. 0.02645 nm
Ans (a)
d. 26.45 nm
71. If rn = 52.9(n2)/Z pm, the radius of Li+2 would be
a. 0.2645 nm
b. 1.798nm
c. 0.1763 nm
Ans (c)
d. 26.23 nm
72. What are the frequency and wavelength of a photon emitted during a
transition from n = 5 state to the n = 2 state in the H atom ?  = 3.29 X 1015
(1/n12 – 1/n22) Hz,  = c/
a. 69.1 X 1014 Hz & 434 Å
b. 6.91 X 1014 Hz & 434 nm
c. 0.691 X 1014 Hz & 434 pm
d. 691 X 1014 Hz & 434 cm
Ans (b)
73. Bohr’s theory was unable to explain
a. Hydrogen spectra
b. Circular orbit
c. Zeeman effect
d. Presence of nucleus in atom
Ans (c)
74. Who was not involed in development of quantum mechanical model
a. Bohr
b. De Broglie
c. Heisenberg
d. Schrodinger
Ans (a)
75. Who confirmed the wave nature of electron ?
a. De Broglie
b. Heisenberg
c. Schrodinger
Ans (d)
d. Davisson & Germer
76. The wave nature of electron is made to use in making
a. electron microscope
b. microscope
c. mass spectrometer
d. U.V / Vis spectrometer
Ans (a)
77. What will be the wavelength of a ball of mass 0.1 Kg moving with a velocity
of 10 m/s ?
a. 6.626 X 10-32 m
b. 6.626 X 10-34 m
c. 6.626 X 10-33 m
d. 6.626 X 10-35 m
Ans (b)
78. If the kinetic energy of electron is 3 X 10-25 J then wavelength of electron is
a. 8967 nm
b. 8697 nm
c. 896.7 nm
d. 89.67 nm
Ans (c)
79. The mass of a photon of light having wavelength 3.6 Å is
a. 6.135 X 10-29 kg
b. 6.135 X 10-30 kg
c. 61.35 X 10-29 kg
d. 6.135 X 10-28 kg
Ans (a)
80. Mathematical representation of Heisenberg’s uncertainty is
a. ∆x ∆p ≤ h/4 b. ∆x ∆p ≥ h/2 c. ∆x ∆p ≥ h/4m d. ∆x m∆v ≤ h/4
Ans (c)
81. The effect of Heisenberg uncertainty principle is significant
a. for motion of macroscopic objects b. for motion of microscopic object
c. for motion of all objects
d. only for motion of microscopic objects & is negligible for that of macroscopic
objects
Ans (d)
82. The value of ∆v ∆x for a object of mass 10-6 Kg is
a. 1023 m2 s-1
b. 1028 m2 s-1
c. 1027 m2 s-1
Ans (b)
d. 1025 m2 s-1
83. The value of ∆v ∆x for an electron is
a. 10-2 m2s-1
b. 10-3 m2s-1
Ans (c)
d. 10-5 m2s-1
c. 10-4 m2s-1
84. A microscope using suitable photons is employed to locate an electron in
an atom within a distance of 0.1 Å. What is the uncertainty involved in the
measurement of its velocity ?
a. 6.79 X 106 ms-1 b. 5.79 X 105 ms-1 c. 5.79 X 102 ms-1 d. 5.79 X 106 ms-1
Ans (d)
85. A golf ball has the mass of 40 g and a speed of 45m/s. If the speed can be
measured within accuracy of 2%. Calculate the uncertainty in position.
a. 1.46 X 10-32 m b. 1.46 X 10-33 m c. 1.46 X 10-34 m d. 1.46 X 10-35 m
Ans (b)
86. The branch of science that takes into account the dual behaviour of matter
is called
a. quantum mechanics
b. quantum theory
c. classical mechanics
d. wave theory
Ans (a)
87. Classical mechanics is based on
a. thermodynamics laws
c. Newton’s laws of motion
Ans (c)
b. faraday’s law
d. all of the above
88. Quantum mechanics was developed by
a. Werner Heisenberg
b. Loui de Broglie
c. Erwin Schrodinger
d. Heisenberg and Schrodinger
Ans (d)
89. For a system such as an atom or a molecule whose energy does not change
with time the Schrodinger equation is written as
a. HΨ = EΨ b. ĤΨ = -EΨ
c. ĤΨ = EΨ d. -ĤΨ = EΨ
Ans (c)
90. The solution of Schrodinger wave equation gives
a. E only
b. Ψ only
c. E and Ψ
Ans (c)
d. E, V and Ψ
91. The Schrodinger wave equation is
a. d2 Ψ/dx2 + d2 Ψ/dy2 + d2 Ψ/dz2 + 82m/h2 (E-V) Ψ = 0
b. 2 Ψ/ x2 + 2 Ψ/y2 + 2 Ψ/z2 + 82m/h (E-V) Ψ = 0
c. 2 Ψ/ x2 + 2 Ψ/y2 + 2 Ψ/z2 + 8m2/h2 (E-V) Ψ = 0
d. 2 Ψ/ x2 + 2 Ψ/y2 + 2 Ψ/z2 + 82m/h2 (E-V) Ψ = 0
Ans (d)
92. The wave function is a mathematical function
a. whose value depends on the coordinates of the electron in the atom
b. it does not carry any physical meaning
c. it is called atomic orbit for one electron system
d. all of the above
Ans (d)
93. The probability of finding an electron at a point within an atom is
proportional to the
a. | Ψ2 | at that point
b.| Ψ2 | at any point
c. Ψ2 at all points
d. all of the above
Ans (a)
94. The energy of hydrogen and hydrogen like species
a. depend only on quantum number n
b. depend on n and l
c. depend on m, n and l
d. none
Ans (a)
95. Ĥ is a mathematical operator called
a. Hamiltonian operator
b. Heisenberg operator
c. Hilton operator
d. Laplacian operator
Ans (a)
96. Ĥ is equal to
a. h2/82m( 2/x2 + 2/y2 + 2/z2 ) + V
b. 82m/h2( 2/x2 + 2/y2 + 2/z2 ) + V
c. -82m/h2( 2/x2 + 2/y2 + 2/z2 ) – V
d. -h2/82m( 2/x2 + 2/y2 + 2/z2 ) + V
Ans (d)
97. r ,  and  are known as
a. polar coordinates
c. spherical coordinates
Ans (b)
b. spherical polar coordinates
d. none
98. R(r) radial function which
a. gives the dependence of orbital upon distance r of the electron from the
nucleus
b. gives the dependence of orbit upon distance r of the electron from the
nucleus
c. gives the dependence of orbital  and 
d. all of the above
Ans (a)
99. R depends upon
a. n
b. l
Ans (c)
c. n and l
100.  and  depends upon
a. l
b. m
Ans (c)
c. l and m
101. R(r) =
a. 1/r2 2/r(r2 Ψ/ r)
c. 1/r /r(r2 Ψ/ r)
Ans (b)
b. 1/r2 /r(r2 Ψ/ r)
d. none
d. l and m
d. n , l , and m
102.  =
a. 1/ r2 sin2 (2 Ψ / 2 )
c. 1/ r2 sin (2 Ψ / 2 )
Ans (a)
b. 1/ r sin (2 Ψ / 2 )
d. 1/ r sin2 (2 Ψ / 2 )
103.  =
a. 1/ r2 sin2 d / d (sin Ψ / )
c. 1/ r sin2 d / d (sin Ψ / )
Ans (d)
b. 1/ r sin d / d (sin Ψ / )
d. 1/ r2 sin d / d (sin Ψ / )
104. The wave function represents the orbital in which
a. radial part gives size and angular part gives shape
b. radial part gives shape and angular part gives size
c. radial part gives distance and angular part gives angle
d. all of the above
Ans (a)
105. One of the important features of the Quantum mechanical model of atom
is
a. The energy of electrons in atom is variable
b. The energy of electrons in atom is unpredictable
c. The energy of electrons in atom is quantised
d. The energy of electrons in atom is constant
Ans (c)
106. What is the direct result of the wave like properties of electrons and are
allowed solutions of Schrodinger wave equation ?
a. The existence of quantised electronic energy levels
b. The existence of orbitals
c. The existence of only one orbit
d. all of the above
Ans (a)
107. All the information about the electron in atom is stored in
a. in its orbit
b. in its orbital function 
2
c. in its | Ψ |
d. all of the above
Ans (b)
108. | Ψ2 | is known as
a. probability amplitude b. square of wave function which is meaningless
c. probability density
d. nodal plane
Ans (c)
109. Qualitatively the orbitals can be distinguished by their
a. size
b. Shape
c. Orientation
d. all of the above
Ans (d)
110. Shape and orientation of orbital means
a. there is more probability of finding electrons along all directions
b. there is less probability of finding electrons along all directions
c. there is less probability of finding electrons along certain directions
d. there is more probability of finding electrons along certain directions than
others
Ans (d)
111. The principle quantum numbers determines
a. the size
b. the energy of orbital
c. for hydrogen atom and hydrogen like species energy and size of orbitals
d. all of the above
Ans (d)
112. The principle quantum number identifies
a. shell
b. Orbital
c. shape of orbital
Ans (a)
d. none
113. The name of ‘l’ is
a. azimuthal quantum no.
c. subsidiary quantum no.
Ans (d)
b. Angular momentum no.
d. all of the above
114. ‘ l ‘ defines
a. size
c. orientation of electron
Ans (b)
b. three dimensional space of orbital
d. all of the above
115. Probability density |2| is
a. probability of circular path around nucleus b. probability per unit volume
c. probability in whole area
d. none
Ans (b)
116. |2|
a. varies from one region to another in space
b. remain constant from one region to another
c. can have +ve or –ve values
d. all of the above
Ans (a)
117. In a plot of radial probability functions against r a 0 stands for
a. a0= n2 h2 / 42me2Z
b. the distance from nucleus where probable density is maximum
c. Bohr’s radius
d. all of the above
Ans (d)
118. Ms refers to
a. the size of orbital
c. orientation of orbital
Ans (d)
b. shape of orbital
d. orientation of spin of electron
119. In the plot of radial wave function versus r for 1s orbital
a. R remains constant with increasing r
b. R approaches infinity as r approaches zero
c. R approaches zero as r approaches infinity
d. R continuously increases with r
Ans (c)
120. In the plot of radial wave function (R or Ψ) versus r for 2s orbital
a. At node the value of R changes from +ve to –ve
b. ns has n – 1 node
c. R first decreases sharply to zero and further increases
d. all of the above
Ans (d)
121. In the plot of the radial density (R 2 or Ψ2 ) versus r for 1s orbital
a. maximum probability near nucleus b. probability increases as r is increased
c. there is one node
d. none
Ans (a)
122. In the plot of the radial density (R 2 or Ψ2 ) versus r for 2s orbital
a. the probability density first increases then decreases
b. the probability density first decreases sharply to zero and again starts
increasing
c. the probability density first decreases sharply to zero and again decreases to
–ve
d.the probability density first decreases slowly to zero and then again
increases sharply
Ans (b)
123. No. of radial nodes in 6s orbital is
a. 3
b. 4
c. 5
Ans (c)
d. 6
124. No. of radial nodes in 4p orbital is
a. 1
b. 2
c. 3
Ans (b)
d. 4
125. The no. of angular nodes in 2p orbital is
a. 1
b. 2
c. zero
Ans (a)
d. none
126. The total number of nodes in 3p orbital is’
a. 0
b. 1
c. 2
Ans (c)
d. 3
127. The total number of nodes in p or d orbitals
a. n-1
b. n + l
c. 2l +1
Ans (a)
d. n +1
128. The total number of nodes is
a. sum of l angular nodes and (n - l) radial nodes
b. sum of l angular nodes and n radial nodes
c. sum of l angular nodes and (n – l - 1) radial nodes
d. sum of (l + 1 ) angular nodes and (n - l) radial nodes
Ans (c)
129. In case of Pz orbital
a. XY plane is a radial nodal plane
c. XZ plane is a angular nodal plane
Ans (b)
b. XY plane is a angular nodal plane
d. YZ plane is a angular nodal plane
130. In case of dxy orbital
a. there is one nodal plane passing through the origin and bisecting XY plane
b. there is one nodal plane passing through the origin and containing Z axis
c. there are two nodal planes passing through the origin and bisecting the XY
plane containing Z axis
d. there are two nodal planes passing through the origin and bisecting the XZ
plane
Ans (c)
131.The no. of angular nodal plane in d orbital is
a. 1
b. 2
c. 3
Ans (b)
d.. 4
132. The no. of degenerate levels in 3d orbitals are
a. 1
b. 3
c. 5
d. 7
Ans (c)
133. Which quantum number is helpful to explain line spectra of multi electron
atoms?
a. Principle quantum no.
b. Azimuthal quantum no.
c. Magnetic quantum no.
d. Spin quantum no.
Ans (d)
134. The electrons in the completely filled shells are known as
a. valence electrons
b. core electrons
c. last electrons
d. all of the above
Ans (b)
135. The electrons that are added to the electronic shell with the highest
principal quantum are called
a. valence electrons b. core electrons c. last electrons
d. all of the
above
Ans (a)
136. The electrons in Ne are
a. valence electrons b. core electrons c. last electrons d. all of the above
Ans (b)
137. The electron from Na to Cl are
a. valence electrons b. core electrons
Ans (a)
c. last electrons d. all of the above
138. After the filling of 6p orbital, according to Auf-bau principal ,
a. 7s , 4f and 6d orbitals takes place b. 7s , 5f and 5d orbitals takes place
c. 7s , 6f and 6d orbitals takes place d. 7s , 5f and 6d orbitals takes place
Ans (d)
139) The total number of orbitls in any orbit is :
(a) 2n
(b) n2
(c) 2n2
(Where n is principal quantum number)
Ans : (b)
(d) n/2
140) How many electrons having opposite spin can remain in any one orbital?
(a) 2
(b) 4
(c) 6
(d) 0
Ans : (a)
141) What is the no. of value of magnetic quantum number (m) having l = 1 ?
(a) 0
(b) 1
(c) 3
(d) 5
Ans : (c)
142) Which orbital is shown by n = 3, l = 2
(a) 3s
(b) 3p
(c) 3d
Ans : (c)
(d) none of these
143) Orbital having n = 3 will have how many orbitals?
(a) 3
(b) 6
(c) 9
Ans : (c)
(d) 12
144) Which will be value of principal quantum number having 18 electrons?
(a) 1
(b) 2
(c) 3
(d) 4
Ans : (c)
145) Which of the following is not fundamental component of an atom?
(a) proton
(b) cyclotron
(c) electrons
(d) neutron
Ans : (b)
146) How may electrons are in the outermost orbit of oxygen O8 ?
(a) 2
(b) 4
(c) 6
(d) 8
Ans : (c)
147) Which of the following does not have electrons (configuration) like that of
inert gas?
(a) O-2
(b) Na+
(c) F(d) F
Ans : (d)
148) What can be the values of spin quantum number?
(a) 1
(b) 0
(c) 2
(d) +1/2
Ans : (d)
149) Which of the following is the absolute mass in gram for an electron?
(a) 9.109 x 10-28
(b) 910.9 x 10-28 (c) 91.09 x 10-28 (d) None of these
Ans : (a)
150) Who discovered proton?
(a) Chadwick
(b) Thomson(c) Goldstein
Ans : (c)
(d) Bohr