Q.1
What is different in isotopes of an element?
  • a) Atomic number
  • b) Mass number
  • c) Number of protons
  • d) Number of electrons
Q.2
In any sub-shell, the maximum number of electrons having same value of spin quantum number is
  • a)
  • b) l + 2
  • c) 2l + 1
  • d) 4l + 2
Q.3
The orbital diagram in which both Pauli's exclusion principle and Hund's rule are violated is ... [ BIT 1992]
  • a)
    ch-1_qn-373choice_img_no1.png
  • b)
  • c)
  • d)
Q.4
Which of the following is violation of Pauli's exclusion principle? [ IIT 1993]
  • a)
    ch-1_qn-374choice_img_no1.png
  • b)
    ch-1_qn-374choice_img_no2.png
  • c)
    ch-1_qn-374choice_img_no3.png
  • d)
    ch-1_qn-374choice_img_no4.png
Q.5
Which of the following sets of quantum numbers represents an impossible arrangement? [ Pb CET 1991]
  • a) n=3, l=2, m=-2, s=1/2
    ch-1_qn-375choice_img_no1.png
  • b) n=4, l=0, m=0, s=1/2
    ch-1_qn-375choice_img_no2.png
  • c) n=3, l=2, m=-3, s=1/2
    ch-1_qn-375choice_img_no3.png
  • d) n=5, l=3, m=0, s=1/2
    ch-1_qn-375choice_img_no4.png
Q.6
How many electrons can have value n=2, l=1, and s=+1/2 in the configuration 1s2 2s2 2p3 [ MLNR 1992]
  • a)1
  • b) 3
  • c)5
  • d)7
Q.7
The de Broglie equation suggest that an electron has .... [ BHU 1992]
  • a) Particle nature
  • b) Wave nature
  • c)Particle - wave nature
  • d)Radiation behavior
Q.8
the number of unpaired electrons in the p-subshell oxygen atom is .... [ Hariyana CEET 1991]
  • a) 3
  • b) 2
  • c)1
  • d)4
Q.9
The value of azimuthal quantum number l=2 represents... [BHU 1993]
  • a) s -orbital
  • b) p -orbital
  • c) d -orbital
  • d) f -orbital
Q.10
Which combinations of quantum numbers n, l, m and s for the electron in an atom does not provide a permissible solution of the wave equation? [ IIT 1992]
  • a)3,2,-2, 1/2
  • b) 3, 3, 1, -1/2
  • c)3, 2, 1, 1/2
  • d)3, 1, 1, -1/2
Q.11
The probability of finding an electron residing in a px orbit is zero [ AIIMS 1991]
  • a) in yz plane
  • b) in the xy plane
  • c)in the y-direction
  • d)in the z-direction
Q.12
For an electron if the uncertainty is velocity is Δv the uncertainty in its position (Δx) is given bt ... [ AIIMS 1994]
  • a)
  • b)
  • c)
  • d)
Q.13
Energy of third orbit of Bohr's atom is ...[PMT 1991]
  • a) -13.6 eV
    ch-1_qn-383choice_img_no1.png
  • b) -3.4 eV
    ch-1_qn-383choice_img_no2.png
  • c) -1.5 eV
    ch-1_qn-383choice_img_no3.png
  • d) None of these
    ch-1_qn-383choice_img_no4.png
Q.14
The electronic configuration of the element which is just above the element with atomic number 43 in the same periodic group is ... [ MLNR 1992]
  • a)1s2 2s2 2p6 3s2 3p6 3d5 4s2
  • b) 1s2 2s2 2p6 3d2 3p6 3d10
  • c)1s2 2s2 2p6 3d2 3p6 3d64s1
  • d)1s2 2s2 2p6 3d2 3p6 3d10 1s1 4p6
Q.15
The electron in an atom{Bihar CEE 1992]
  • a) moves randomly around the nucleus
  • b) has fixed space around the nucleus
  • c)is stationary in various energy levels
  • d)moves around its nucleus in definite energy level
Q.16
If electron, hydrogen, helium and neon nuclei are all moving with the velocity of light, then the wavelengths associated with these articles are in order
  • a) electron > hydrogen > helium >neon
  • b) electron > helium &hydrogen > neon
  • c)electron < hydrogen
  • d)neon < hydrogen < helium ≤electron
Q.17
The value of Plank's constant is .... [ Harayana CET 1991]
  • a) 6.6 ×10⁻³² g m² sec
  • b) 6.6 ×10⁻³⁴ kg m² sec-1
  • c) 6.6 ×10⁻³³ kg m² sec-1
  • d) 6.6 ×10⁻³⁴ g m² sec-1
Q.18
Which of the following relates to photos both as wave motion and as a stream of particles{IIT 1992]
  • a)Interference
  • b) E=mc2
  • c)Diffraction
  • d)E=hν
Q.19
The number of d electrons in Fe2+ ( at.no of Fe=26) is not equal to that of the .....[ MLNR 1993]
  • a) p-electrons in Ne( at. no 10)
  • b) s- electrons in Mg (at. no.=12)
  • c)d electrons in Fe
  • d)p electrons in Cl-
Q.20
The electronic configuration of Cu ( atomic number 29) is
  • a) 1s2 2s2, 2p6, 3s2, 3p6, 4s2, 3d9
  • b) 1s2 2s2, 2p6, 3s2, 3p6, 3d10 4s2,
  • c) 1s2 2s2, 2p6, 3s2, 3p6, 4s2,4p6,5s2, 5p1
  • d)1s2 2s2, 2p6, 3s2, 3p6, 4s2 4p6 3d3
Q.21
Which of the following is never true for cathode rays? [ CBSE PMT 1994]
  • a) They posses kinetic energy
  • b) They are electromagnetic waves
  • c) They produce heat
  • d) They produce mechanical pressure
Q.22
The number of electrons in 3d shell for element with atomic number 26 is [ Hariyana CEET]
  • a)4
  • b) 6
  • c)8
  • d)10
Q.23
Which of the following pairs are isobars? [ KECT 1992]
  • a) 92U235 , 94Pu239
  • b) 36Kr83 , 36Kr84
  • c)10Ne19 , 9F19
  • d)58Ce139 , 58Ce140
Q.24
When the azimuthal quantum number has a value of l=1, the shape of the orbital is [ MP PRT 1993]
  • a) Unsymmetrical
  • b) Spherically symmetrical
  • c)Dumb-bell
  • d)Complicated
Q.25
Total possible values for magnetic quantum number for the values of l=3 is ..... [ Haryana CET 1991]
  • a) 3
  • b) 1
  • c) 5
  • d) 7
Q.26
The order of filling of electrons in the orbital's of an atom will be [ CBSE PMT 1991]
  • a)3d, 4s, 4p, 4d, 5s
  • b) 4s, 3d, 4p, 5s, 4d
  • c)5s, 4p, 3d, 4d, 5s
  • d)3d, 4p, 4s, 4d, 5s
Q.27
Which of the following series of lines is found in UV region of the atomic spectrum of hydrogen/ [ EAMCET 1991]
  • a) Balmar series
  • b) Paschen series
  • c)Brackett series
  • d)Lyman series
Q.28
6C 14 and 7 N 14 may be classified as .. [ Pb CET sample paper 1993]
  • a) Isotopes
  • b) Isotones
  • c)Isobars
  • d)Isoelectronic
Q.29
The electron was shown experimentally to have wave properties by ... [ CBSE PMT 1994]
  • a) de Broglie
  • b) Davisson and Germer
  • c) N. Bohr
  • d) Schrodinger
Q.30
If the radius of first Bohr's orbit be ao, then the radius of the third orbit would be [ MP PMT 1998]
  • a)3 ×ao
  • b) 6 ×ao
  • c)9 ×ao
  • d)(1/9) ×ao
Q.31
Number of protons, neutrons and electrons in the element 89X231 is ...{AFMC 1997]
  • a) 89, 89, 242
  • b) 89, 142, 89
  • c)89, 71, 89
  • d)89, 231, 89
Q.32
The radius of the atom is of the order of ... [ MP PMT 1995]
  • a) 10-10 cm
  • b) 10-13 cm
  • c)10-15 cm
  • d)10-8 cm
Q.33
Bohr's model of atom conflict with ... [ DPMT 1994]
  • a) Pauli's exclusion principle
  • b) Heisenberg's uncertainty principle
  • c) max plank's quantum theory
  • d) all above three
Q.34
The first emission line in the atomic spectrum of hydrogen in the Balmer series appears at ... [ pb. PMT 1996]
  • a)
  • b)
  • c)
  • d)
Q.35
Which of the following statements is incorrect? [ AMU 1997]
  • a) Cathode rays carry negative charge
    ch-1_qn-405choice_img_no1.png
  • b) frequency of X-ray is higher than that of microwaves
    ch-1_qn-405choice_img_no2.png
  • c)Unit for wave number is m-1
    ch-1_qn-405choice_img_no3.png
  • d)Threshold frequency is the same for all metals
    ch-1_qn-405choice_img_no4.png
Q.36
Number of nodal plane 'd' orbital has .... [ KCET 1996]
  • a) 1
  • b) 2
  • c)3
  • d)0
Q.37
The charge of the atom having 17 protons, 18 neutrons and 18 electrons is [ KCET 1994]
  • a) +1
  • b) -1
  • c) -2
  • d) Zero
Q.38
The maximum number of electrons in an atom with l=2 and n=3 is ..[PMP PET 1998]
  • a)2
  • b) 6
  • c)12
  • d)10
Q.39
When the value of azimuthal quantum number , l=2, value of 'n' will be .... [ CPMT 1995]
  • a) 3
  • b) 4
  • c)5
  • d)any one of these
Q.40
The heaviest particle is ....[ DPMT 1994]
  • a) Meson
  • b) Neutron
  • c)Electron
  • d)Proton
Q.41
The number of electrons and neutrons of an element is 18 and 20 respectively. Its mass number is .... [CPMT 1997]
  • a) 2
  • b) 17
  • c) 37
  • d) 38
Q.42
Which of the following is the cause of late discovery of neutron? [ AIIMS 1998]
  • a)Neutron is charge less particle
  • b) Neutron is highly unstable particle
  • c)neutron in the nucleus moves very fast
  • d)All of these
Q.43
What do you mean by degenerate orbitals? ... [ CBSE PMT 19996]
  • a) Orbitals having equal energy
  • b) Orbitals having equal wave function
  • c)Orbital having equal energy but different wave function
  • d)Orbitals having equal energy and equal wave function
Q.44
Consider the following ionsNi2+Co2+Cr2+Fe3+ Atomic number Cr=24, Fe - 16, Co=27, Ni=28 The correct sequence of the increasing order of the number of unpaired electrons is ....
  • a) 1, 2, 3, 4
  • b) 4, 2, 3, 1
  • c) 1, 3, 2, 4
  • d) 3, 4, 2, 1
Q.45
Wavelength associated with electron motion ... [ BHU 1998]
  • a)increases with increase in speed of electron
  • b) remains same irrespective of speed of electron
  • c)decreases with increase of speed of electron
  • d)is zero
Q.46
Which orbital of carbon can absorb photon but not emit it?{CPMT 1997]
  • a) 1s
  • b) 2s
  • c)3p
  • d)2p
Q.47
Atomic weight of an element is not necessarily whole number because... [ DCE 1994]
  • a) It contains electrons, protons and neutrons
    ch-1_qn-419choice_img_no1.png
  • b) It contains allotropic forms
    ch-1_qn-419choice_img_no3.png
  • c) atoms are no longer considered indivisible
    ch-1_qn-419choice_img_no4.png
  • d) it contains isotopes
Q.48
Planck's constant has the same dimensions as that of ... [ AIIMS 1998]
  • a)power
  • b) work
  • c)radiation energy
  • d)angular momentum
Q.49
The value of quantum numbers n, l, and m for 5th electron of Born will be
  • a) n=1, l=0, m=-1
  • b) n=2, l=1, m=-1
  • c)n=2, l=2, m=-1
  • d)n=1, l=2, m=-1
Q.50
The hydride ion is isoelectric with ..... [ AFMC 1995]
  • a) H+
  • b) He+
  • c)He
  • d)Be
0 h : 0 m : 1 s