A certain atom has 26 protons, 26 electrons, and 30 neutrons. What is its mass number?
  • 26
  • 30
  • 52
  • 56
What is the nucleon number of sodium?
  • 11
  • 23
  • 12
What is the neutron number of the sodium atom?
  • 23
  • 12
  • 11
  • 22
The atom has 24 atomic mass and 14 neutrons. How many electron does it have.
  • 24
  • 10
  • 14
  • 12
Which of the following statements is incorrect about the structure of an atom?i. The whole mass of an atom is concentrated in the nucleusii. The atom is an indivisible particleiii. The atom as a whole is neutraliv. All the atoms are stable in their basic stateChoose the right option among the following:
  • (i) and (iii)
  • only (ii)
  • (ii) and (iv)
  • none of these
An element has 5 valence electron , what is its valency?
  • 3
  • 4
  • 2
  • 1
An atom has four shells and 19 protons in its atom , what is its valency?
  • 1
  • 2
  • 3
  • 4
How many valence electrons are there in Nitrogen?
  • 7
  • 5
  • 6
If an electron is removed, an ion becomes
  • An atom
  • Positive
  • Negative
  • Neutral
How many valence electrons are in an atom of Ar?
  • 2
  • 8
  • 4
  • 1
How the sub atomic particles like Proton is different from electron?
  • (a)An electron is much heavier than a proton.
  • (b)An electron carries more charge than a proton.
  • (c) A proton can be easily removed from the atom, but not an electron.
  • (d) A proton is positively charged, whereas an electron is negatively charged
Which of the following is NOT the correct explanation of Thompson’s atomic model?
  • (a)The atom is positively charged sphere.
  • (b)Electrons are embedded in the positive sphere.
  • (c)The positive and negative charges balance each other.
  • (d)Protons and neutrons are embedded in the center of the sphere.
Rutherford conducted an experiment to study the structure of atom. He passedpositively charged alpha particles through a thin gold foil. He studied the angle of deflectionof the alpha particles. He noticed that most of the alpha particles passed through the goldfoil without any deflection. What can be concluded from the observation?
  • (a) Most of the space in an atom is empty.
  • (b) Atoms have electrons, protons, and neutrons.
  • (c) The nucleus of the atom is situated at the center.
  • (d) Atoms do not have positively charged particles.
Which of the following CAN NOT be the maximum number of electrons in a given shellaccording to the Bohr & Bury’s rule for electronic configuration:
  • (a) 2
  • (b) 6
  • (c) 18
  • (d) 32
The atomic number of sodium (Na) is 11. How many valence electrons does sodiumhave?
  • (a) 1
  • b) 2
  • (c) 7
  • (d) 8
The atomic number of Sulphur (S) is 16. Identify the number of electrons in each shell ofSulphur.
  • (a)2, 8, 6
  • (b)2, 8, 8
  • (c)2, 2, 8, 4
  • (d)2, 4, 8, 2
Which elements have a valency of 2?
  • (a) Be and Si
  • (b) Si and Cl
  • (c) Be and O
  • (d) Cl and O
Which element would be inert in nature?
  • (a) Element with 2 electrons
  • (b) Element with 9 electrons
  • (c) Element with 12 electrons
  • (d) Element with 20 electrons
The image shows the scientific notation of sodium. What is the atomic mass of Na?
  • (a)11
  • (b)12
  • (c)23
  • (d)34
Which isotope is used in the nuclear power plants to generate electricity?
  • Uranium 235
  • Iodine 131
  • Cobalt 60
  • Uranium 238
Who discovered the electron?
  • Rutherford
  • Chadwick
  • Thomson
  • Goldstein
What was the source of alpha particles in Rutherford scattering experiment?
  • Hydrogen nucleus
  • Argon nucleus
  • Helium nucleus
  • None of these
Why was the Thomson’s Model of an atom failed?i. It could not explain the screening of negative charges from that of positiveii. It did not tell about the presence of electronsiii. It did not give an idea about the discrete energy levelsiv. It explained the atom as a whole to be electrically neutral.
  • Only (iii)
  • Both (i) & (iii)
  • Only (i)
  • Only (i)
What property of an element determines its chemical behaviour?
  • Size of an element
  • Valency of an element
  • Molar mass of the element
  • None of these
Which of the following does not match the characteristics of an Isotope?
  • Isotopes of some elements are radioactive
  • Isotopes are the atoms of different elements
  • Isotopes differ in number of neutrons
  • Isotopes differ in number of neutrons
Which of the two will be chemically more reactive, Sulphur(S) with atomic number 16 or Chlorine (Cl) with atomic number 17?
  • Chlorine
  • Sulphur
  • Both are equally reactive
  • Can’t say
Which scientist gave the concept of fixed energy levels around the nucleus?
  • Ernest Rutherford
  • Neils Bohar
  • J.J.Thomsan
  • None of these
What prevents an atom from being collapsed?
  • The nuclear forces
  • Movement of electrons in discrete energy levels
  • The electron-electron repulsions
  • All of these
Which radioactive element is used in the treatment of cancer?
  • Iodine-131
  • Uranium-234
  • Plutonium-239
  • Cobalt-60
Why do most of the elements try to participate in the chemical combinations?i. To gain more electronsii. To achieve Inert Gas configurationiii. To complete their octetiv. To complete their inner shells
  • Both (i) & (iii)
  • Both (ii) & (iii)
  • Only (ii)
  • Both (i) & (iv)
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