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1) Bohr’s model of atom was based upon:
a) Electromagnetic wave theory.
b) Planck’s quantum theory
c) Both a and b
d) None of these.
ANSWER : Planck’s quantum theory
2) Which among the following is an example of an object possessing the
character of both wave and particle?
a) Piece of chalk.
b) Piece of iron ball.
c) Molecule.
d) All of these.
ANSWER : All of these.
3) Two particles C and D are in motion. If the wavelength of particle C is 5
x 10-8m. Calculate the wavelength of particle D if its momentum is
half of C.
a) 10-7m
b) 10-5m
c) 10-9m
d) 10-6m
ANSWER : 10-7m
4) Calculate the frequency of the particle wave, if the kinetic energy of
sub-atomic particle is 5.85 x 10-25 J. (h = 6.66 x 10-34 kg
m2 s-1)
a) 1.76 x 108 s-1
b) 1.76 x 109 s-1
c) 2.34 x 108 s-1
d) 2.34 x 109 s-1
ANSWER : 1.76 x 109 s-1
5) The mass of an electron is taken as 10-30 kg. The kinetic
energy of an electron is 5 x 10-5 eV. Calculate the wavelength of
the wave associated with the electron.
a) 1.73 x 10-7 m
b) 2.06 x 10-7 m
c) 1.65 x 10-7 m
d) 3.0 x 10-9 m
ANSWER : 1.65 x 10-7 m
6) The mass and wavelength of a moving body is 0.1 mg and 3.31 x 10-29
m respectively. Calculate its kinetic energy. (h = 6.625 x 10-34 J
sec)
a) 2 x 10-5 J
b) 2 x 10-3 J
c) 3 x 10-3 J
d) 3 x 10-5 J
ANSWER : 2 x 10-3 J
7) Heisenberg’s uncertainly principle is of great significance for:
a) Only microscopic particles.
b) Only macroscopic particles.
c) All the particles.
d) None of these.
ANSWER : Only microscopic particles.
8) Calculate the uncertainly in the position of an electron if the
uncertainly in its velocity is 5.7 x 105 m/sec. (h = 6.6 x 10-34
kg m2 s-1, mass of electron = 9.1 x 10-31 kg)
a) + 10-10 m
b) – 10 -10 m
c) ± 10-10 m
d) None of these.
ANSWER : ± 10-10 m
9) Calculate the uncertainly in the velocity of a moving bullet of mass 10g,
if the uncertainly in the position is 10-5 m.
a) 6.13 x 10-28 ms-1
b) 5.75 x 10-26 ms-1
c) 8.03 x 10-26 ms-1
d) 5.25 x 10-28 ms-1
ANSWER : 5.25 x 10-28 ms-1
10) The branch of science based upon Newton’s laws of motion is called as:
a) Classical mechanics
b) Wave mechanics
c) Quantum mechanics.
d) Both a and c.
ANSWER : Classical mechanics
11) Which among the following is an incorrect statement about the principle
quantum number?
a) It gives the average distance of the electron from the nucleus.
b) It determines the size of the electron cloud.
c) It determines the energy of the electron in hydrogen atom.
d) None of these.
ANSWER : None of these.
12) The electrons present in any main shell of a multi-electron atom do not
have the same energy because:
a) They move along different paths.
b) They move along same path.
c) They have same angular momentum.
d) Both b and c.
ANSWER : They move along different paths.
13) Degenerate orbitals are the orbitas of the:
a) Same subshell having different energy.
b) Same subshell having equal energy.
c) Different subshell having different energy.
d) None of these.
ANSWER : Same subshell having equal energy.
14) Calculate the energy of the first stationery state of Li2+ if
the ionisation energy of He+ is 19.6 x 10-18 J atom-1.
a) +2.13 x 10-17 J atom-1
b) -2.13 x 10-17 J atom-1
c) +4.41 x 10-17 J atom-1
d) -4.41 x 10-17 J atom-1
ANSWER : -4.41 x 10-17 J atom-1
15) The graph of probability versus distance is:
a) A straight line.
b) Linear.
c) A curve.
d) None of these.
ANSWER : A curve.
16) ………….. among the following has maximum number of unpaired electrons.
a) Ni3+
b) Fe2+
c) Cu+
d) Zn
ANSWER : Fe2+
17) The atomic number of nitrogen and oxygen is 7 and 8 respectively.
Calculate the total number of electrons in a nitrate ion.
a) 31
b) 23
c) 32
d) 38
ANSWER : 32
18) Calculate the number of unpaired electrons present in the ground state
of Fe3+. (At.no of Fe =26)
a) 5
b) 8
c) 2
d) 3
ANSWER : 5
19) The numerical value of Planck’s constant is:
a) 6.6 x 10-25 J sec.
b) 6.6 x 10-36 J sec.
c) 6.6 x 10-50 J sec.
d) 6.6 x 10-34 J sec.
ANSWER : 6.6 x 10-34 J sec.
20) De-Broglie equation applies to:
a) Electrons only.
b) Protons only.
c) Neutrons only.
d) All the material objects in motion.
ANSWER : All the material objects in motion.
21) The equation ? = h/m ? was given by:
a) Heisenberg
b) De- Broglie.
c) Newton.
d) Planck.
ANSWER : De- Broglie.
22) ………….. has sp2 hybridization.
a) CO2
b) Co
c) N2O
d) SO2
ANSWER : SO2
23) The ion that is isoelectronic with CO is:
a) CN-
b) N2+
c) O2-
d) O2+
ANSWER : CN-
24) Which among the following is paramagnetic?
a) NO
b) O2-
c) N2-
d) All of these
ANSWER : All of these
25) The radius for the first excited state (n = 2) orbit is 2.12 Å. Find the
Bohr radius for the hydrogen atom (n = 1) in Å.
a) 0.700
b) 1.530
c) 0.530
d) 2.271
ANSWER : 0.530
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