General knowledge - General science (Chemistry MCQs With Answers) Part 3

This is our third collection of chemistry multiple choice question with answers based on measurements and atomic structure if you want to improve your knowledge about this topic, please read it properly and remember.


gk general science
GK general science 

Chemistry MCQs with Answers) Part 3 (Measurements And Atomic Structures )

General Knowledge - General Science



101: In an atomic nucleus, neutrons and protons are held together by

A. gravitational forces
B. exchange forces
C. coulomb forces
D. magnetic forces
Answer: Option B

102:'No two electrons in an atom can have the same set of four quantum numbers' is

A. Newton's law
B. Bohr's law
C. Aufbau principle
D. Pauli's exclusion principle
Answer: Option D

103: According to Avogadro's Hypothesis, the smallest particle of an element or a compound, that can exist independently, is called ___ _.

A. a molecule
B. a cation
C. an anion
D. an atom
Answer: Option A

104: Atoms of an element differ from those of all other elements in

A. atomic number and electronic configuration
B. number of neutrons and number of valence electrons
C. atomic number and number of valence electrons
D. number of neutrons and electronic configuration
Answer: Option A

105: Nuclear fission is caused by the impact of

A. neutron
B. proton
C. deuteron
D. electron
Answer: Option A

106: Which of the following rays are more penetrating?

A. Beta rays
B. Alpha rays
C. Gamma rays
D. X-rays
Answer: Option C

107: How many colors the sunlight spectrum has?

A. Three
B. Seven
C. Four
D. Five
Answer: Option B

108:'Bar' is the unit of

A. temperature
B. heat
C. atmospheric pressure
D. current
Answer: Option C

109: One Joule is equal to

A. 105 ergs
B. 103 ergs
C. 107 ergs
D. 1011 ergs
Answer: Option C

110: Kilowatt is a unit to measure

A. work
B. power
C. electricity
D. current
Answer: Option B

111: Electric current is measured by

A. commutator
B. anemometer
C. ammeter
D. voltmeter
Answer: Option C

112: Chronometer measures

A. color contrast
B. sound waves
C. time
D. water waves
Answer: Option C

113: The light-year is a measurement of

A. speed of airplanes
B. speed of light
C. Stellar distances
D. speed of rockets
Answer: Option C

114: Very small time intervals are accurately measured by

A. White dwarfs
B. Quartz clocks
C. Atomic clocks
D. Pulsars
Answer: Option C

115: One kilometer is equal to how many miles

A. 0.84
B. 0.5
C. 1.6
D. 0.62
Answer: Option D

116: A kilohertz is a unit which measures

A. power used by a current of one ampere
B. electromagnetic radio wave frequencies
C. voltage
D. electric resistance
Answer: Option B

117: One horsepower is equal to

A. 746 watts
B. 748 watts
C. 756 watts
D. 736 watts
Answer: Option A

118: What is the unit for measuring the amplitude of a sound?

A. Decibel
B. Coulomb
C. Hum
D. Cycles
Answer: Option A

119: Reading of a barometer going down is an indication of

A. snow
B. storm
C. intense heat
D. rainfall
Answer: Option D

120: Decibel is the unit for

A. speed of light
B. radio wave frequency
C. intensity of sound
D. intensity of heat
Answer: Option C

121: One fathom is equal to

A. 6 feet
B. 6 meters
C. 60 feet
D. 100 cm
Answer: Option A

122: Fathom is the unit of

A. sound
B. depth
C. frequency
D. distance
Answer: Option B

123: A nautical mile is a unit of distance used in

A. navigation
B. road mile
C. astronomy
D. measuring the boundaries of a nation
Answer: Option A

124: A knot is a unit of speed of which of the following?

A. Airplane
B. Light waves
C. Ship
D. Sound waves
Answer: Option C

125: Electromagnetic radiations produced from nuclear reactions are

A.  α - rays
B.   β - rays
C.   x — rays
D.   γ - rays
Answer: Option B

126: The nature of positive rays depends on

A.  The nature of residual gas
B.  The nature of the discharge tube.
C.  The nature of the electrode
D.   All of the above
Answer: Option A

127: Anode rays were discovered by

A.   J.J. Thomson
B.   Rutherford
C.   J. Stoney
D.   Goldstein
Answer: Option D

128: Which one of the following represents 2p subshell?

A.   n = 1,L = 0
B.   n = 1, L = 1
C.   n = 2, L = 1
D.   n = 2, L = 0
Answer: Option C

129: when 6d orbital is complete, the entering electron goes into

A.   7p
B.   7d
C.   7f
D.   7s
Answer: Option A

130: The most electronegative element is

A.   Fluorine
B.   Bromine
C.   Chlorine
D.   Iodine
Answer: Option A

131: When α — particles are sent through a thin metal foil, most of them go straight through the foil because

A.   α — particles are positively charged.
B.   α — particles move with high velocity
C.   Most of the space is empty is an atom.
D.   All of the above
Answer: Option C

132: The atomic mass of an element is equal to the sum of

A.   Electron and proton
B.   Electron and neutron
C.   Proton and neutron
D.   None of the above
Answer: Option C

133: Neutron is a fundamental particle which carries

A.   No charge and mass of one unit
B.   A charge —1 unit and no mass.
C.   No charge and no mass.
D.   A charge of +1 and mass of l unit
Answer: Option A

134: The maximum number of. electrons that can be accommodated by p — orbital is

A.   10
B.   6
C.   14
D.   2
Answer: Option B

135: Which of the following statement Is wrong about electron

A.   It is a particle
B.   It has wave-like property
C.   It emits energy while moving in orbit.
D.   Its motion is affected by the magnetic field.
Answer: Option C

136: The nature of cathode rays was identified by

A.   William Crook
B.   J.J. Thomson
C.   J. Perrin
D.   Hitiroff
Answer: Option B

137: Principle Quantum number describes

A.   The orientation of an orbital.
B.   Shape of orbital
C.   Size of orbital
D.   Spin of orbital
Answer: Option C

138: Cathode rays are deflected by

A.   Neither electric nor magnetic field.
B.   Both electric and magnetic field
C.   An electric field only.
D.   A magnetic field only
Answer: Option B

139: Neutrons were discovered by

A.   Faraday
B.   J.J. Thomson
C.   Dalton
D.   Chadwick
Answer: Option D

140: The mass of the electron as determined by J.J. Thomson is

A.   9.1 X 10-25 kg
B.   9.1 X 10 -10gm
C.   9.1 X 10-31 kg.
D.   9.1 X 10 -18gm
Answer: Option C

 141: If the electronic structure of an oxygen atom is written as 1s2 2s2 2p4 it would violate

A. Hund’s rule
B. Paulis exclusion principle
C. Both Hund’s and Pauli’s principles
D. None of these
Answer: Option D

142: Number of nodal planes for f-orbital are

A.  3
B.  2
C. 1
D.  0
Answer: Option A

143: One Bohr magneton equals

A. ehc /4Ï€ n
B. e c /4hπ m
C. hc /m e4Ï€
D. eh /4Ï€ mc
Answer: Option D

144: Three isotopes of an element have mass numbers M, (M + 1) and (M + 2). If the mean mass number is (M + 0.5) than which of the following ratio may be accepted for M, (M + 1), (M + 2) in that order.

A. 1: 1: 1
B. 4: 1: 1
C. 3: 2: 1
D. 2: 1: 1
Answer: Option B

145: A possible set of quantum numbers for the last electron added to a gallium atom (Z = 31) in its ground state is

     n    l   m   ms
_______________
A. 4   1   –1   +1/2
B. 4   0   0   –1/2
C. 3   2   +2   +1/2
D. 3   0   0   –1/2
Answer: Option A

146: The angle made by the angular momentum vector of an electron with z-axis is given by

A. cosθ = l/m
B. cosθ = √l/m
C. cos θ = √[(l+1)/m ]
D. cosθ = m/√l(l+1)
Answer: Option D

147: The distance between 3rd and 2nd orbit of a hydrogen atom is

A. 2.646 ×10–8 cm
B. 2.116 ×10–8 cm
C. 1.058 ×10–8 cm
D. 0.529 × 10–8 cm
Answer: Option A

148: An atom has four unpaired electrons. The total spin of this atom will be

A. 1
B. 1.5
C. 2
D. 4
Answer: Option C

149: For a ‘ d ‘ electron, the orbital angular momentum is

A. √6 h
B. √2 h
C. h
D. 2 h
Answer: Option A

150: Which of the following pairs can form the correct set of isosters?

A. MgS, CaF2
B. C6H6, B3N3H6
C. CO, N2O
D. All the above

Answer: Option B


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