The orientation of an atomic orbital is determined by the: a) Principal quantum number b) Magnetic quantum number c) Spin quantum number d) Azimuthal quantum number Answer: b
Which of the following is NOT a cation? a) Aluminium ion b) Copper ion c) Sulphate ion d) Zinc ion Answer: c
Two electrons in the same orbital are distinguished by their: a) Magnetic quantum number b) Spin quantum number c) Principal quantum number d) Azimuthal quantum number Answer: b
If two electrons occupy the same orbital, they must have: a) Same spin b) Opposite spin c) Either same or opposite spin d) No spin Answer: b
How is a cation formed? a) By gaining an electron b) By losing an electron c) By gaining a proton d) By losing a proton Answer: b
Green plants absorb maximum light in which wavelength range? a) Green and yellow b) Red and blue c) Green and red d) Blue and yellow Answer: b
How is an anion formed? a) By gaining an electron b) By losing an electron c) By gaining a proton d) By losing a proton Answer: a
Which orbital has a dumbbell shape? a) s-orbital b) p-orbital c) d-orbital d) f-orbital Answer: b
An atom has 7 electrons in the M-shell and 18 neutrons in the nucleus. What is its mass number? a) 25 b) 27 c) 35 d) 43 Answer: c
Who discovered the proton? a) Rutherford b) Miescher c) Goldstein d) Cavendish Answer: a
The nucleus of an atom contains: a) Only protons b) Protons and neutrons c) Neutrons and electrons d) Only neutrons Answer: b
The atomic number of carbon is 6 and its atomic mass is 12. The number of protons is: a) 6 b) 12 c) 18 d) 0 Answer: a
Which of the following is NOT electromagnetic in nature? a) Cathode rays b) X-rays c) Gamma rays d) Infrared rays Answer: a
The Lyman series in the hydrogen atom lies in the: a) X-ray region b) Ultraviolet region c) Visible region d) Infrared region Answer: b
The total energy of a revolving electron in an atom: a) Cannot be negative b) Can be any value above zero c) Can never be positive d) Is always positive Answer: c
Which subatomic particle has no electric charge? a) Electron b) Proton c) Neutron d) All of the above Answer: c
The statement, “It is impossible to determine simultaneously both position and velocity of an electron” refers to: a) Heisenberg’s uncertainty principle b) Pauli’s exclusion principle c) Aufbau principle d) De Broglie hypothesis Answer: a
The correct formula of potassium ion in its stable state is: a) K⁺ b) K²⁺ c) K²⁻ d) K⁻ Answer: a
The mass of one mole of a substance (in grams) is called: a) Nuclear mass b) Atomic mass c) Mass number d) Molar mass Answer: d
An element with mass number 226 and atomic number 88 has how many neutrons? a) 88 b) 138 c) 214 d) 50 Answer: b
The presence of unpaired electrons in nitrogen is explained by: a) Hund’s rule b) Aufbau principle c) Pauli’s exclusion principle d) Heisenberg’s uncertainty principle Answer: a
According to Aufbau principle, the correct order of orbital energies is: a) 4p < 3d < 4s b) 4s < 4p < 3d c) 4s < 3d < 4p d) 3d < 4s < 4p Answer: c
The number of neutrons in a hydrogen atom is: a) 1 b) 0 c) 2 d) 3 Answer: b
The basic particles that make up an atom are: a) Proton, electron, meson b) Proton, electron, photon c) Proton, electron, neutron d) Proton, electron, deuteron Answer: c