Q.1
Electron configuration of four metals are given below. Which of the corresponding element would be most paramagnetic? [ AMU 1997]
  • a) 1s2, 2s2, 2p6
  • b) 1s2, 2s2 2p1
  • c) 1s2, 2s2, 2p5
  • d) 1s2, 2s2 2p4
Q.2
An electron has magnetic quantum number as -3, what is its principal quantum number
  • a)1
  • b) 2
  • c)3
  • d)4
Q.3
The electron configuration of 21Sc is ...{BHU 1997]
  • a) 1s2 2s2 2p6 2s2 3p64s23d1
  • b)1s2 2s2 2p6 2s2 3p64s13d2
  • c)1s2 2s2 2p6 2s2 3p64s03d3
  • d)1s2 2s2 2p6 2s2 3p64s23d2
Q.4
Which of the following has maximum number of unpaired electrons? [ IIT 1996]
  • a) Mg2+
  • b) Ti3+
  • c)V3+
  • d)Fe2+
Q.5
Bohr's radius of Hydrogen atom is ... [ Haryana CEET 1994]
  • a) 0.529 × 10⁻⁸ m
  • b) 0.529 ×10⁻¹⁰ m
  • c) 5.29 ×10⁻⁸ m
  • d) 5.29 × 10⁻¹⁰ m
Q.6
the electrons identified by quantum numbers n and l (i) n=4, l=1 (ii) n=4, l=0 (iii) n=3 , l=2 (iv) n=3, l=1 can be placed in order of increasing energy, from the lowest to highest, as
  • a)(iv) < (ii) < (iii) <(i)
  • b) (ii) < (iv) < (i) < (iii)
  • c)(i) < (iii) < (ii) < (iv)
  • d)(iii) < (i) < (iv) < (ii)
Q.7
The outer electronic configuration of 3s2 3p5 is possessed by... [ KECT 1997]
  • a) O
  • b) Cl
  • c)Br
  • d)Ar
Q.8
The paramagnetic character follows the order .... [ CBSE MPT 1997]
  • a) Mg > Cr > Zn
  • b) Fe > Zn >Co
  • c)Cr > Fe > Zn
  • d)Hg > Mn > Fe
Q.9
Bohr's model was modified by ... [ EAMCET 1995]
  • a) Sommerfeld
  • b) Rutherford
  • c) Dalton
  • d) Pauli
Q.10
ratio of mass of proton and electron is ... [ BHU 1998]
  • a)infinite
  • b) 1.8 × 10+3
  • c)1.8
  • d)none of these
Q.11
Brackett series are produced when the electrons from outer orbits jump to .... [ Pb CET 1997]
  • a) 2 nd orbit
  • b) 3 rd orbit
  • c)4 th orbit
  • d)5 th orbit
Q.12
heisenberg's Uncertainty Principle is applicable to ... [ BHU 1994]
  • a) atoms only
  • b) electrons only
  • c)nucleus only
  • d)any moving object
Q.13
An element M has an atomic mass 19 and atomic number 9, its ion is represented by [ IIT 1996]
  • a) M+
  • b) M2+
  • c) M-
  • d) M2-
Q.14
Which of the following has more unpaired d-electrons? [ CBSE PMT 1999]
  • a)Zn+
  • b) Fe3+
  • c)Cu3+
  • d)Cu+
Q.15
The energy of an electron in the first Bohr orbit of H atom is -13.6 eV. the possible value(s) of the excited state(s) for electrons in Bohr orbits of hydrogen is (are) .. [ IIT 1998]
  • a) -3.4 eV
  • b) - -4.2 eV
  • c)-6.8 eV
  • d)+6.8 eV
Q.16
the configuration 1s2, 2s2 2p5 3s1 shows .....[AIIMS 1997]
  • a) ground state of fluorine
  • b) excited state of fluorine
  • c)excited state of Neon atom
  • d)excited sate of O2-
Q.17
Azimuthal quantum number determines the .... [ BHU 1995]
  • a) size
  • b) spin
  • c) orientation
  • d) angular momentum of orbitals
Q.18
Which is not true with respect to cathode rays? [ kerala CEE 2001]
  • a)A stream of electron
  • b) Charged particles
  • c)Move with speed same as that of light
  • d)can be deflected by magnetic fields
Q.19
In H atom electron jumps from 3rd to 2nd energy level, the energy released is ... [ AFMC 1997]
  • a) 3.03 ×10⁻¹⁹ J/atom
  • b) 1.03 ×10⁻¹⁹ J/atom
  • c)3.03 ×10⁻¹² J/atom
  • d)6.06 ×10⁻¹⁹ J/atom
Q.20
For which of the following species, Bohr's theory is not applicable? [ DEC 2000]
  • a)Be3+
  • b) Li2+
  • c)He2+
  • d)H
Q.21
Chloride ion and potassium ion are isoelectronic then [ KCET 2002]
  • a) their size are same
  • b) Chloride ion is bigger than potassium ion
  • c)potassium ion is relatively bigger
  • d)depends upon the other cation or anion
Q.22
The wave number of first line of Balmaer series of hydrogen is 15200 cm-. The wave number of first Balmaer line of Li2+ ion is ..[ IIT 1992]
  • a)15200 cm-1
  • b) 60800 cm-1
  • c)76000 cm-1
  • d)136800 cm-1
Q.23
In the Bohr's orbit, what is the ratio of total kinetic energy and total energy of the electrons ... [ Rajasthan PMT 2002]
  • a) -1
  • b) -2
  • c) +1
  • d) +2
Q.24
Identify the least stable among the following ... [ IIT 2002]
  • a)Li-
  • b) Be-
  • c)B-
  • d)C-
Q.25
In a Bohr's atomic model, when an electron jumps from n=3 to n=1 how much energy will be emitted? [ CBSE PMT 1996]
  • a) 2.15 ×10⁻¹¹ ergs
  • b) 2.389 ×10⁻¹² ergs
  • c)0.239 ×10⁻¹⁰ erg
  • d)0.1936 ×10⁻¹⁰ erg
Q.26
An electron moving with velocity 'v' is found to have a certain value of de-broglie wave length. the velocity to be possessed by the neutron to have the same de-Broglie wave length is ...
  • a) 1840/v
  • b) 1840v
  • c) v/1840
  • d) v
Q.27
Which of the following atom has no neutron in its nucleus? [ CPMT 2000]
  • a)Helium
  • b) Lithium
  • c)Protium
  • d)Tritium
Q.28
The frequency of yellow light having wavelength 600nm is ... [MPPMT 2002]
  • a) 5.0 ×1014Hz
  • b) 2.5 ×107 Hz
  • c)5 ×107 Hz
  • d)2.5 × 1014 Hz
Q.29
The energy of the first electron in helium will be ...[ Bihar CEE 2002]
  • a) -13.6 eV
  • b) -54.4 eV
  • c)-5.44 eV
  • d)zero
Q.30
The quantum number +1/2 and -1/2 for the electron spin represent ... [ IIT 2001]
  • a)rotation of the electron in clockwise and anticlockwise direction respectively
  • b) rotation of the electron in anticlockwise and clockwise direction respectively
  • c)magnetic moment of the electron pointing up and down respectively
  • d)two quantum mechanical spin states which have no classical analogues
Q.31
the ratio of ionization energy of H and Be+3 is ...{pb CET 1996]
  • a)1:1
  • b)1:3
  • c)1:9
  • d)1:16
Q.32
A 200 g cricket ball is thrown with a speed 3×103 cm/sec, what will be its de Broglie wavelength? [ Pb. CET 1986]
  • a) 1.1 ×10⁻³² cm
  • b) 2.2 ×10⁻³² cm
  • c) 0.55 × 10⁻³² cm
  • d) 11.0 × 10⁻³² cm
Q.33
In Cu ( At. No 29) [Haryana CEET 2000]
  • a)13 electrons have spin in one direction and 16 electrons in other direction
  • b) 14 electrons have spin one direction and 15 electrons in other direction
  • c)one electron can have spin only in the clockwise direction
  • d)none of the above is correct
Q.34
In hydrogen atom, energy of first excited state is -3.4eV. then find out the Kinetic energy of the same orbit of hydrogen atom [ CBSE PMT 2002]
  • a) +3.4 eV
  • b) +6.8 eV
  • c)-13.6 eV
  • d)+13.6 eV
Q.35
t 200°C, the velocity of hydrogen molecule is 2.0×105 cm/sec. In this case the de Broglie wavelength is about... [ CBSE PMT 1990]
  • a) 1 Ao
  • b) 1000 Ao
  • c) 100 Ao
  • d) 10 Ao
Q.36
In the ground state, an element has 13 electrons in its M-shell. The element is ... [ EAMCET 2001]
  • a)Cobalt
  • b) Chromium
  • c)Nickel
  • d)Iron
Q.37
If the nitrogen atom had electron configuration 1s7, it will would have energy lower than that of the normal ground state configuration 1s2 2s2 2p3 because the electrons would be closer to the nucleus. Yet 1s7 is not observed. It violets ... [ IIT 2002]
  • a) Heisenberg's uncertainty principle
  • b) Hund's rule
  • c)Pauli's exclusion principle
  • d)Bohr postulate of stationary orbits
Q.38
The energy of hydrogen atom in ground state is -13.6 eV. the energy of the level corresponding to the quantum number n=5 is ...[ CBSE PMT 1990]
  • a) -0.54 eV
  • b) -5.40 eV
  • c)-0.85 eV
  • d)-2.72 eV
Q.39
The kinetic energy of an electron accelerated from rest through a potential difference of 5V will be ... [ Kerals CEE 2001]
  • a) 5 J
  • b) 5 erg
  • c) 5 eV
  • d) 80 eV
Q.40
Among the following groupings which represents the collection of isoelectronic species?... [ CBSE PMT 2000]
  • a)NO+, C22- O2-, CO
  • b) N2, C22-, CO, NO
  • c)CO, NO+, CN-, C22-
  • d)NO, CN-, N2, O2-
Q.41
As the nuclear change increases from Neon to calcium, the orbitals energies ... [ kerala MEE]
  • a)increases
  • b)increases very rapidly
  • c)increases very slowly
  • d)fall
Q.42
Ratio of energy of photon of wavelength 3000Å and 6000Å is ... [AFMC 1999]
  • a) 3 :1
  • b) 2 :1
  • c)1:2
  • d)1:3
Q.43
the Bohr orbit radius for H-atom ( Z=1) ia approximately 0.53Å. the radius for the first excited state orbit is ...[ CBSE PMT 1998]
  • a) 0.13 Å
  • b) 1.06 Å
  • c) 4.77 Å
  • d) 2.12 Å
Q.44
For how many orbitals, the quantum number n=3, l=2, m=+2 are possible? [ CBSE Med. 2001]
  • a)1
  • b) 2
  • c)3
  • d)4
Q.45
Rutherford's experiment which established the nuclear model of the atom used a beam of .... [IIT 2002]
  • a) β particles which impinged on metallic foil and got absorbed
  • b) γ -ray which impinged on a metal foil and ejected electrons
  • c)helium atoms, which impinged on a metal foil and got scattered
  • d)helium nuclei, which impinged on a metal foil and got scattered
Q.46
What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n=4 to n=2 in the He+ spectrum [ IIT 1993]
  • a)n=4 to n=1
  • b) n=3 to n=2
  • c)n=3 to n=1
  • d)n=2 to n=1
Q.47
Light of wavelength λ shines on a metal surface with intensity x and the metal emits y electrons per second of average energy z. What will happen to y and Z if x is doubled.
  • a) y will be doubled but z will remain same
  • b) both y and z will be doubled
  • c) y will remain same and z will be doubled
  • d) y will be doubled and z will become half
Q.48
A 5d orbital has ... [ Kerala MEE 2000]
  • a)one node
  • b) two nodes
  • c)three nodes
  • d)four nodes
Q.49
An element M has an atomic mass 19 and atomic numberIts ion is represented by ... [ manipal PMT 2001]
  • a) M+
  • b) M2+
  • c)M-
  • d)M2-
Q.50
The radius of hydrogen atom in the ground state is 0.53Å. the radius of Li2+ ion ( atomic number 3 ) in similar state is ...[ CBSE PMT 1995]
  • a) 0.17 Ao
  • b) 1.06 Ao
  • c) 0.53Ao
  • d) 0.265Ao
0 h : 0 m : 1 s