Structure of the atom MCQs with Answers

Question-1. Which of the following statements does not belong to Bohr?s model?

1. Energy of the electrons in the orbit is quantized
2. The electrons in the orbit nearest to the nucleus is the lowest energy
3. Electrons revolve around the nucleus in different orbits having fixed energies
4. The electrons radiate energy during revolution due to force of attraction between nucleus and electrons

Question-2. Which of the following statements does not belong to Bohrs model?

1. The electrons radiate energy during revolution due to force of attraction between nucleus and electrons
2. Energy of the electrons in the orbit is quantized
3. The electrons in the orbit nearest to the nucleus is the lowest energy
4. Electrons revolve around the nucleus in different orbits having fixed energies

Question-3. Who discovered the electron?

1. Rutherford
2. Chadwick
3. Thomson
4. Goldstein

Question-4. Which of the following has a charge of +1 and a mass of 1 amu?

1. A neutron
2. A proton
3. An electron
4. A helium nucleus

Question-5. 2, 8,1 is the electronic configuration of

1. lithium
2. potassium
3. helium
4. sodium

Question-6. A chlorine atom has ____ protons, _____ electrons and _____ neutrons

1. 18, 17, 18
2. 17, 18, 18
3. 17, 17, 18
4. 17, 17, 17

Question-7. An aluminium ion carries _____ units of positive charge

1. 2
2. 3
3. 1
4. 4

Question-8. An atom that becomes charged by gaining or losing an electron is called

1. cation
2. anion
3. ion
4. electron

Question-9. Atoms combine to attain stable configuration by

1. sharing electrons
2. sharing, accepting or donating electrons
3. donating electrons
4. accepting electrons

Question-10. Cations are carry

1. both positive and negative charges
2. neutral charge
3. negative charge
4. positive charge

Question-11. Compound formed by sharing electrons is called

1. ionic compound
2. electrovalent compound
3. covalent compound
4. coordinate compound

Question-12. In a chemical reaction, ___________ participate

1. valence electrons
2. all electrons of the atom
3. protons
4. electrons and protons

Question-13. In a CO2 molecule, the total number of electrons shared between a carbon and two oxygen atoms are

1. 8
2. 4
3. 2
4. 6

Question-14. In the formation of NaCl, sodium atom

1. receives an electron
2. shares an electron
3. does not react
4. donates an electron

Question-15. Noble gases do not react with other elements to form compounds because

1. they are unstable
2. they are gases
3. they are stable
4. they are already compounds

Question-16. Number of electrons in the outermost shell of carbon is

1. 4
2. 6
3. 3
4. 8

Question-17. Oxygen atom becomes an oxide ion by

1. losing two electrons
2. gaining two electrons
3. gaining one electron
4. losing one electron

Question-18. Sodium and chlorine atoms are held together in NaCl by

1. electromagnetic force
2. gravitational force
3. electrostatic force
4. magnetic force

Question-19. Sodium ion (Na+) has ____ number of electrons

1. 10
2. 12
3. 11
4. 13

Question-20. The electronic configuration of oxygen

1. 2, 7
2. 2, 6
3. 2, 4, 2
4. 4, 4

Question-21. The electronic configuration of the element with atomic number 19 is

1. 2,8,7
2. 2,9,8
3. 2,8,8,1
4. 2,10,7

Question-22. The noble gases from the following are

1. O2, N2, H2
2. Cl, F, Br
3. He, Ne, Ar
4. Na, K, Ca

Question-23. The number of electrons shared between two oxygen atoms is

1. 2
2. 1
3. 2
4. 4

Question-24. The shell which has two electrons is

1. first shell
2. second shell
3. third shell
4. fourth shell

Question-25. The valence electrons of an element are reponsible for

1. Physical properties of an element
2. Chemical properties of an element
3. Both the properties
4. None of these

Question-26. Total number of electrons in an atom of nitrogen is

1. 9
2. 6
3. 8
4. 7

Question-27. When chlorine atom becomes chloride ion it

1. loses an electron gains an electron
2. gains an electron
3. electrostatic force
4. magnetic force

Question-28. 7N15 and 8O16 are a pair of

1. Isotopes
2. Isobars
3. Isotones
4. None of these

Question-29. A natural phenomenon that supports the experimental conclusion that atoms are divisible is

1. allotropy
2. radioactivity
3. cracking
4. none of these

Question-30. A proton is identical to

1. the nucleus of berellium
2. the nucleus of helium
3. a molecule of a hydrogen
4. an atom of hydrogen

Question-31. According to J.J Thomson, an atom is a positively charged sphere. Which sub-atomic particles is embedded in it?

1. Electrons
2. Canal Rays
3. Protons
4. Neutrons

Question-32. According to the atomic theory

1. matter is not created but can be destroyed in a chemical reaction
2. matter is neither created nor destroyed in a chemical reaction
3. matter is created but not destroyed in a chemical reaction
4. matter can be created and destroyed in a chemical reaction

Question-33. Amongst element X (2,8,6) and (2,8,8) which is more reactive and why ?

1. X because it is a metal
2. Y because it is non metal
3. X because it has 6 valence electrons
4. Y because it is gas

Question-34. An atom which has a mass number of 14 and has 8 neutrons is an

1. isotope of oxygen
2. isobar of oxygen
3. isotope of carbon
4. isobar of carbon

Question-35. An element has electronic configuration 2,8,4 it will be classified as

1. Metal
2. Non metal
3. Metalloid
4. None of these

Question-36. An neutral element A has 3 electrons, the atomic number of an element is _______

1. 1
2. 2
3. 5
4. 3

Question-37. An particle is

1. a hydrogen molecule
2. a helium nucleus
3. an electron
4. a proton

Question-38. Atomic mass of an element is the number of times by which the mass of its atom is greater than

1. 1/12 th mass of carbon atom
2. 1/12 th mass of hydrogen atom
3. 1/12 th mass of oxygen atom
4. 1/12 th mass of helium atom

Question-39. Atomic number of an atom is the

1. number of protons + number of neutrons
2. number of neutrons
3. number of electrons + number of protons
4. number of protons

Question-40. Atomic number of an element is denoted by

1. X
2. A
3. Z
4. N

Question-41. Based on his experiments, Rutherford concluded that the positive charge of an atom is

1. spread all over the atom
2. revolves around the atom in orbits
3. exists in the empty space
4. present in the nucleus

Question-42. Cathode rays have

1. Mass only
2. Charge only
3. Both mass and charge
4. Neither mass nor charge

Question-43. Cathode raysget deflected in a electric field towards

1. Positive plate
2. Negative Plate
3. No deflection takes place
4. First towards negative plate and then towards positive plate

Question-44. Composition of the nuclei of two atomic species are given: CBSE Class 10 Chemistry Structure of The Atom MCQs-The mass number of x and Y and their relation is

1. 16,16; isotopes
2. 17,15; isotopes
3. 17,15; isotopes
4. 16,16; 1sobars

Question-45. Each of the stationary orbits are associated with

1. A certain amount of velocity.
2. A certain amount of mass.
3. A certain amount of energy.
4. A certain amount of force.

Question-46. For an element with atomic number 19, the 19th electron will occupy

1. L-shell
2. M-shell
3. N-shell
4. K-shell

Question-47. How many electrons in a Hydrogen (H) atom:

1. One
2. Two
3. Three
4. Four

Question-48. How many electrons, protons and neutrons are present in X+, if atomic number of X is 19 and its mass number is 39

1. E=19, P=19, N= 20
2. E=18, P=19, N= 20
3. E=18, P=19, N= 19
4. E=19, P=20, N= 20

Question-49. If K, L, M, N shells of an atom are full, the total number of electrons in the atom are

1. 60
2. 26
3. 42
4. 36

Question-50. In a neutral atom, the number of protons is equal to

1. half the number of electrons
2. number of electrons
3. number of neutrons
4. number of neutrons + number of electrons

Question-51. In a neutral atom, the number of protons is equal to

1. Number of electrons
2. Half the number of electrons
3. Number of neutrons
4. Number of electrons and neutrons

Question-52. In an atom, the constituent electrons:

1. Do not move
2. Are uniformly distributed
3. Move around the nucleus in fixed energy levels
4. Move around the nucleus in a random way.

Question-53. In the periodic table, the elements are arranged in the

1. increasing order of atomic mass
2. decreasing order of atomic number
3. alphabetical order
4. increasing order of atomic number

Question-54. Isotopes are

1. atoms of the same element
2. atoms of different elements
3. molecules of the same element
4. radicals of the same element

Question-55. Isotopes of an element do not have

1. Same number of element
2. Same physical properties
3. Same chemical properties
4. Same elecrical charge on the nucleus

Question-56. Isotopes of an element have

1. the same physical properties
2. different chemical properties
3. different number of neutrons
4. different atomic numbers

Question-57. K is the symbol of

1. potassium
2. calcium
3. krypton
4. aluminium

Question-58. Light energy is treated as a form of matter because it consists of

1. Photons or bundles of energy
2. Electrons or wave like matter
3. Neutrons
4. None of the Above

Question-59. Mass of neutron is equal to

1. that of an electron
2. half the mass of an electron
3. the mass of a proton
4. half the mass of a proton

Question-60. Members of which of the following have similar chemical properties?

1. Isotope
2. Isobars
3. Allotropes
4. Both isotopes and allotropes

Question-61. Na+ has 12 neutrons and 10 electrons. Which of the following statements is correct?

1. Na+ has atomic number 10 and mass number 22.
2. Na+ has atomic number 11 and mass number 23.
3. Na+ has atomic number 10 and mass number 23.
4. Na+ has atomic number 11 and mass number 22.

Question-62. Neutron Possesses

1. Positive charge
2. No charge
3. Negative charge
4. None of the above.

Question-63. Neutrons were discovered by

1. Joseph Thomson
2. James Chadwick
3. Ernest Rutherford
4. John Dalton

Question-64. Rutherford directed a stream of _____ on a thin gold leaf in the scattering experiment

1. alpha particles
2. beta particles
3. gamma particles
4. X-rays

Question-65. The atomic number of an element having mass number 23 and number of neutron 12 is ________

1. 23
2. 11
3. 12
4. 35

Question-66. The atomic number of an element is determined by

1. the number of electrons in one atom
2. the number of neutrons in one atom
3. the valency of the element
4. the number of protons in one atom

Question-67. The atomic number of the element with maximum number of unpaired electrons is:

1. 23
2. 33
3. 15
4. 26

Question-68. The charge/ mass ratio of electron

1. Depends on the nature of the electrodes
2. Depends upon nature of the gas
3. Remains constant
4. Depends on both nature of the gas and nature of the electrode

Question-69. The e/m ratio of an electron for all types of substances is

1. constant
2. less than one
3. greater than one
4. zero

Question-70. The electron should be filled in the orbital in accordance with the increasing order of their energy. This statement is related with

1. Affbau principle
2. Pauli principle
3. Hund's principle
4. Plank's rules

Question-71. The electronic configuration of an atom with atomic number 19 is:

1. 2, 8, 8, 1
2. 1, 2, 2, 8
3. 2, 8, 9
4. 2, 10, 7

Question-72. The electronic configuration of Cl- ion is:

1. 2,8,8
2. 2,8,7
3. 2,8,6
4. 2,8,8,1

Question-73. The electronic configuration of Cl(17) is

1. 2,8,7
2. 2,2, 8,5
3. 2,8,2,5
4. 2,2,5,8

Question-74. The element with the same atomic and mass number is

1. oxygen
2. hydrogen
3. helium
4. carbon

Question-75. The energy associated with an orbit

1. increases with his distance from the nucleus
2. decreases with increase in the distance from nucleus
3. remains constant whatever may be the distance
4. none of these

Question-76. The fluorescence on the walls of discharge tube is due to:

1. Cathode rays
2. Anode rays
3. Canal rays
4. None of the above

Question-77. The highest value of e/m ratio for anode rays is observed when the discharge tube is filled with

1. N2
2. H2
3. He
4. Ar

Question-78. The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?

1. 13
2. 10
3. 14
4. 16

Question-79. The isotope deuterium of hydrogen has

1. No neutrons and one proton
2. One neutrons and two protons
3. One electron and two neutron
4. One proton and one neutron

Question-80. The isotope of hydrogen that contains the same numer of protons and neutrons in its nucleus is called

1. Protium
2. Deutrium
3. Tritium
4. None of these

Question-81. The isotope used to remove the brain tumours and treatment of cancer is

1. U-235
2. Na-24
3. Iodine
4. C0-60

Question-82. The mass number of an element is denoted by

1. A
2. Z
3. X
4. N

Question-83. The mass number of an element is the sum of the number of

1. Proton and electron
2. Electron and neutrons
3. Protons, electrons and neutrons
4. Protons and neutrons

Question-84. The mass of an electron is

1. 1837 times the mass of proton
2. 1/1837 th times the mass of hydrogen atom
3. 1/1831 th times the mass of oxygen atom
4. 1/1837 th times the mass of carbon atom

Question-85. The mass of proton is about the same as that of

1. carbon atom
2. an electron
3. hydrogen ion
4. oxygen atom

Question-86. The nucleons are

1. Protons and electrons
2. Neutrons and electrons
3. Protons and neutrons
4. None of these

Question-87. The nucleus of an atom contains:

1. Protons
2. Electrons
3. Protons and neutrons
4. Neutrons

Question-88. The nucleus of the hydrogen atom is called as

1. Neutron
2. Electron
3. Proton
4. Nucleons

Question-89. The number of electrons in the outer shell of the most stable or inert atoms is

1. 1
2. 4
3. 6
4. 8

Question-90. The scientist who measured the mass and charge of an electron was

1. Goldstein
2. Rutherford
3. Dalton
4. Thomson

Question-91. The scientist who put forward the atomic theory in 1808 was

1. Dalton
2. Lavoiser
3. Galileo
4. Thomson

Question-92. The smallest fundamental particle, of an atom with unit negative charge is called

1. Electron
2. Proton
3. Neutron
4. Alpha-particle

Question-93. The symbol of the element sodium is

1. Si
2. S
3. Na
4. N

Question-94. The valency of an element is its

1. electronic configuration
2. combining capacity
3. atomic number
4. mass number

Question-95. What are the essential conditions for the production of anode rays?

1. High voltage and low pressure
2. High voltage and high pressure
3. Low voltage and high pressure
4. Low voltage and low pressure

Question-96. What is an electron?

1. A wave
2. A particle
3. Either of two, depending on how it is observed
4. Neither of these

Question-97. What prevents an atom from being collapsed?

1. The nuclear forces
2. Movement of electrons in discrete energy levels
3. The electron-electron repulsions
4. All of these

Question-98. What property of an element determines its chemical behaviour?

1. Size of an element
2. Valency of an element
3. Molar mass of the element
4. None of these

Question-99. When a gold foil is bombarded by a beam of a particle, only a few of them get deflected whereas most go straight undeflecte

1. This is because
2. The force of attraction exerted on a particles by the electrons is insufficient
3. The volume of nucleus is much smaller than that of the atom
4. The force of repulsion acting on the fast moving a particles is very smalld) The neutrons have no effect on a particles

Question-100. When a gold foil is bombarded by a beam of a particle, only a few of them get deflected whereas most go straight undeflecte This is because

1. The volume of nucleus is much smaller than that of the atom
2. The force of attraction exerted on a particles by the electrons is insufficient
3. The force of repulsion acting on the fast moving a particles is very small
4. The neutrons have no effect on a particles

Question-101. When alpha-particles are sent through a thin metal foil, most of them go straight through the foil because

1. alpha-particles are positively charged
2. alpha-particles are much smaller than electrons
3. alpha-particles move with low velocity
4. most part of the atom is empty

Question-102. When an a-particle is emitted

1. Element moves 2 places to the right in the periodic table
2. Element moves one place to the left
3. Element moves 2 places to the left in the periodic table
4. Elements maintains its position

Question-103. Which amonght the following statement is true?

1. a rays are cathode rays
2. Electrons make up the cathode rays
3. Protons make up the cathode rays
4. Electron magnetic radiation make up the cathode rays

Question-104. Which of the following are isobars: 18Ar40, 19 K39 ,20 Ca40, 19[K+]39

1. 18 Ar40,20 Ca40,
2. 19 K39 , 19+[K+]39
3. 18 Ar40,19 K39
4. 18 Ar40,19 K39 ,20 Ca40

Question-105. Which of the following are isotopes: 1 1 H, 1 2D,1 3 T,1 1 H+

1. 1 1 H, 1 2D,1 3 T
2. 1 1 H, 1 1 H+
3. 1 1 H, 1 2D,1 1 H+
4. 1 1 H, 1 3 T,1 1 H+

Question-106. Which of the following are positively charged ions: CBSE Class 10 Chemistry Structure of The Atom MCQs-1

1. A and B
2. C and D
3. B and D
4. D and F

Question-107. Which of the following correctly represents the electronic distribution in the Mg atom?

1. 3, 8, 1
2. 2, 8, 2
3. 1, 8, 3
4. 8, 2, 2

Question-108. Which of the following does not have 8 valence electrons

1. He
2. Ne
3. Ar
4. Cl

Question-109. Which of the following does not have 8 valence electrons

1. He
2. Ne
3. Ar
4. Cl-

Question-110. Which of the following does not have one electron in its valance shell

1. Na
2. Ca
3. Li
4. H

Question-111. Which of the following elements has the electron configuration 2?

1. Magnesium
2. Helium
3. Sodium
4. Hydrogen

Question-112. Which of the following has an equal number of neutrons and protons?

1. Hydrogen
2. Deuterium
3. Fluorine
4. Chlorine

Question-113. Which of the following is the correct electronic configuration for magnesium?

1. 2, 8, 1
2. 2, 8, 3
3. 2, 8, 4
4. 2, 8, 2

Question-114. Which of the following isotope is used in the treatment of blood cancer?

1. P-32
2. I-131
3. Co-60
4. any of these

Question-115. Which of the following pairs are isotopes?

1. Oxygen and ozone
2. Ice and steam
3. Nitric oxide and nitrogen dioxide
4. Hydrogen and deuterium

Question-116. Which of the following particles was discovered first?

1. Neutron
2. Electron
3. Proton
4. Meson

Question-117. Which of the following statement is correct about proton?

1. It is an ionized Hydrogen atom
2. It is the nucleus of deuterium
3. It is an ionized hydrogen molecule
4. It is an a particle with unit positive charge

Question-118. Which of the following statement is true?

1. Elements combine in fixed proportion by volume to form compounds
2. Elements combine in fixed proportions by weights to form compounds
3. elements combine in fixed proportion by mass to form compounds
4. None of these