Q.1
The spectrum of He is expected to be similar to that of [ AIIMS 1980]
  • a) H
  • b) L+
  • c)Na
  • d)He+
Q.2
The value of Plank's constant is .... [ EAMCET 1983]
  • a) 6.6256 ×10⁻²⁷ erg sec
  • b) 66.256 × 10⁻²⁷ erg sec
  • c) 6.02 ×10⁻¹⁵ erg
  • d) 3.01 ×10⁻²³ erg
Q.3
The triad of nuclei which is isotonic is ... [ IIT 1988]
  • a)6C14, 7N15, 9F17
  • b)6C12, 7N14, 9F19
  • c)6C14, 7N14, 9F17
  • d)6C14, 7N14, 9F19
Q.4
The number of spherical nodes in 3p orbitals are ... [ CBSE PMT 1988]
  • a) one
  • b) three
  • c)two
  • d)four
Q.5
The radius of second Bohr's orbital is ... [ BHU 1989]
  • a) 0.053nm
  • b) 0.0534/4 nm
  • c)0.053 ×4 nm
  • d)0.053 ×20 nm
Q.6
If the mass number of an element is W and its atomic number is N, then [ CPMT 1989]
  • a) Number of e-1=W-N
  • b) Number of 1H1=W -N
  • c) Number of 0n=W -N
  • d) Number of 0n1=N
Q.7
Number of electrons in the outermost orbit of the element of atomic number 15 is ... [ CPMT 1988]
  • a)7
  • b) 5
  • c)3
  • d)2
Q.8
The maximum number of electrons in a subshell is given by the expression [ CBSE PMT 1989]
  • a) 4l-2
  • b) 4l+2
  • c)2l+1
  • d)2n2
Q.9
An orbit with quantum number n=4 , l=3, m=0, and s=-(1/2) is called [ Pb. CET sample paper 1990]
  • a) 3s orbital
  • b) 3p orbital
  • c)4d orbital
  • d)4f orbital
Q.10
Which of the following is correct in case of p-orbitals? [ EAMCET 1990]
  • a) They are spherical
  • b) They have strong directional character
  • c) They have no directional character
  • d) They are five fold degenerate
Q.11
If r is the radius of first orbit, the radius of nth orbit of H-atom is given by .... [ CBSE PMT 1988]
  • a)rn2
  • b) rn
  • c)r/n
  • d)r2n2
Q.12
Indicate which electronic configuration amongst the following correctly represents sulphur atom [ BIT Ranchi 1989]
  • a) 1s2 2s2 2p6 3s2 3p2 3d2
  • b)1s2 2s2 2p6 3s2 3p2 4s2
  • c)1s2 2s2 2p6 3s2 3p6 4s14p1
  • d)1s2 2s2 2p6 3s2 3p4
Q.13
If the speed of electron in the Bohr's first orbit of hydrogen atom be x, then speed of the electron in the 3rd orbit is .... [ IIT 1990]
  • a) x/9
  • b) x/3
  • c)3x
  • d)9x
Q.14
Spectrum produced due to transition of an electron from M to L shell is ... [ AFMC 1990]
  • a) absorption
  • b) emission
  • c) X-ray
  • d) continuous
Q.15
The orbital diagram in which aufbau principle is violated is
  • a)
    ch-1_qn-333choice_img_no1.png
  • b)
    ch-1_qn-333choice_img_no2.png
  • c)
    ch-1_qn-333choice_img_no3.png
  • d)
    ch-1_qn-333choice_img_no4.png
Q.16
Number of electrons in -CONH2 is .. [ AMU 1988]
  • a) 22
  • b) 24
  • c)20
  • d)28
Q.17
In a set of degenerate orbitals, the electron distribute themselves to retain like spins as far as possible. This statement is attributed to [ Pb. CET 1989]
  • a) Pauli exclusion principle
  • b) Aufbau principle
  • c)Hand's rule of maximum multiplicity
  • d)Slater rules
Q.18
Which of the following statements concerning the four quantum numbers is false [ Pb. CET 1990]
  • a) n gives idea of the size of an orbital
  • b) l gives the shape of an orbital
  • c) m gives the energy of the electron in the orbital
  • d) s gives the direction of spin of the electron in the s-orbit
Q.19
The electron in K-shell of the atom will differ in ....{MLNR 1988]
  • a)principal quantum number
  • b) azimuthal quantum number
  • c)magnetic quantum number
  • d)spin quantum number
Q.20
An ion has 18 electrons in the outermost shell, it is ... [CBSE PMT 1990]
  • a) Cu+
  • b) Th4+
  • c)Cs+
  • d)K+
Q.21
If the atomic number of nickel and copper are 28 and 29 respectively, which of the following does the electric configuration 1s2 2s2 2p6 3s2 3p6 3d10 represent [ Pb. CET 1988]
  • a)Cu+
  • b) Cu2+
  • c)Ni2+
  • d)Ni
Q.22
Which of the following statement does not form a part of Bohr's model of hydrogen atom [ CBSE PMT 1989]
  • a) Energy of the electrons in the orbits is quantized
  • b) The electron in the orbit nearest the nucleus has lower energy
  • c) Electrons revolve in different orbits around the nucleus
  • d) The position and velocity of the electrons in the orbit cannot be determined simultaneously
Q.23
The size of nucleus is measured in ....[EAMCET 1988]
  • a)amu
  • b) Angstrom
  • c)Fermi
  • d)cm
Q.24
Which of the sets of quantum numbers is impossible? [ Pb.CET 1989]
  • a) n=3, l=0, m=-1
  • b) n=3, l=2, m=+1
  • c)n=3, l=1 m=-1
  • d)n=3, l=2,m=0
Q.25
How many spherical nodes are present in 4s orbital in hydrogen atom? [ Pb. CET 1990]
  • a) 0
  • b) 1
  • c)2
  • d)3
Q.26
The ratio between the neutrons in C and Si with respect to atomic masses 12 and 28 is .... [ EAMCET 1990]
  • a) 2:3
  • b) 3:2
  • c) 3:7
  • d) 7:3
Q.27
When the value of the azimuthal quantum number is 3, the magnetic quantum number can have values [ MP PMT 1987]
  • a)+1, -1
  • b) +1, 0, -1
  • c)+2, +1, 0, -1, -2
  • d)+3, +2, +1, 0, -1, -2, -3
Q.28
Mass of the neutron is of the order of ... [ MLNR 1988]
  • a) 10-23 kg
  • b) 10-24 kg
  • c)10-26 kg
  • d)10-27 kg
Q.29
If electron has spin quantum number of +1/2 and magnetic quantum number -1, it cannot be present in [ CBSE PMT 1989]
  • a) d-orbital
  • b) f-orbital
  • c)p-orbital
  • d)s-orbital
Q.30
The magnetic quantum number represents...... [ MLNR 1990]
  • a) size of the orbital
  • b) spin angular momentum
  • c) orbital angular momentum
  • d) spatial orientation of orbital
Q.31
The total spin resulting from a d7 configuration is .... [ Pb CET 1989]
  • a)3/2
  • b) 1/2
  • c)2
  • d)1
Q.32
The correct set of quantum number for the unpaired electron of chlorine atom is [ JIPMER 1994]
  • a) n=2, l=1, m=0
  • b) n=2, l=1, m=1
  • c)n=3, l=1, m=-1
  • d)n=3, l=0, m=0
Q.33
on Q351) The energy of an orbit in hydrogen atom is given by the relationWhich of the following properties represents the constant in the above relation? [Pb CET 1990]
ch-1_que_no-351_img_no1.png
  • a) Electron affinity
  • b) Ionization energy
  • c)Electronegativity
  • d)Bond energy
Q.34
the spectrum of He+ is expected to be similar to that of .... [ AIITMS 1990]
  • a) Hydrogen
  • b) Li+
  • c) Na
  • d) He
Q.35
Magnetic quantum number for the valence electron in sodium atom is equal to.... [ CPMT 1988]
  • a)3
  • b) 2
  • c)1
  • d)0
Q.36
Number of unpaired electrons in N2+ is ..[ CBSE PMT 1989]
  • a) 2
  • b) 0
  • c)1
  • d)3
Q.37
p orbital can accommodate .... [ MLNR 1990]
  • a) 4 electrons
  • b) 6 electrons
  • c)2 electrons with parallel spin
  • d)2 electrons with opposite spin
Q.38
The atomic weight of an atom is due to... [ AFMC 1990]
  • a) Electrons and protons
  • b) Electrons and neutrons
  • c) Neutron and protons
  • d) Electron, neutron and protons
Q.39
For a dumbell shaped orbital, the value of l is ... [ CPMT 1987]
  • a)0
  • b) l
  • c)+1 or -1
  • d)3
Q.40
Which of the following is the smallest in size [ IIT 1989]
  • a) N3-
  • b) O2-
  • c)F-
  • d)Na+
Q.41
the total number of electrons that can be accommodated in all the orbitals having principal quantum number 2 and Azimuthal quantum number 1 ... [ CPMT 1989]
  • a) 2
  • b) 4
  • c)6
  • d)8
Q.42
The energy of an electron in the nth Bohr orbit of hydrogen atom is ...{CBSE PMT 1992]
  • d)13.6/n eV
  • a) 13.6/n⁴ eV
  • b) 13.6/n³ eV
  • c)13.6/n² eV
Q.43
According to Bohr's theory, the angular momentum for an electron in 5th orbit is ...[BHU 1992]
  • a) 2.5h /π
  • b) 5h/π
  • c)25h/π
  • d)5π/2π
Q.44
Which of the statements is incorrect for an electron that has the quantum number n=4 and m=2? [ MLNR 1993] when m=2, then l can not be0 or 1 Answer: (d)
  • a) The electron may have the quantum number s=+1/2
  • b) The electron may have the quantum number l=2
  • c) The electron may have the quantum number m=-2
  • d) The electron may have the quantum numbers l=0, 1, 2
Q.45
Pick out the isoelectronic structures from the following I) CH3+II) H3O+III) NH3IV) CH3- [ IIT 1993
  • a) I and II
  • b) III and IV
  • c)I and III
  • d)II, III and IV
Q.46
Which of the following pair has same electronic structure? [ CPMT 1992]
  • a) Ca, Ar
  • b) Mg, Na+
  • c)Ag, Sn
  • d)Ar, Cl-
Q.47
The quantum numbers for the designation of 3d are ... [ Pb CET 1991]
  • a) n=3, m=-3
  • b) n=3, l=3
  • c) n=4, l=1
  • d) n=3, l=2
Q.48
The atomic number of an element having the valence shell electronic configuration 4s2 4p6 is ... [ PMPMT 1991]
  • a)35
  • b) 36
  • c)37
  • d)38
Q.49
The maximum number of electrons in all those orbitals for which principal quantum number is 3 and azimuthal quantum number 2 is
  • a) 2
  • b) 8
  • c)10
  • d)18
Q.50
Which of the following represents the correct set of quantum numbers of a 4d electron? [ MLNR1992]
  • a) 4, 3, 2, +1/2
  • b) 4, 2, -2, 0
  • c)4, 3, -2, +1/2
  • d)4, 2, 1, -1/2
0 h : 0 m : 1 s