Atomic Structure

1

The mass number of an atom is determined by

  1. the number of protons only
  2. adding the number of neutrons and number of electrons
  3. adding the number of protons and number of electrons
  4. adding the number of neutrons and number of protons
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2

Which of the following pairs represents isoelectronic ions

  1. Mg2+, Ca2+
  2. Na+, K+
  3. K+, Mg2+
  4. Ca2+, S2-
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3

Which one among the following contains the most neutrons?

  1. 6129Cu
  2. 5926Fe
  3. 6030Zn2+
  4. 6130Zn
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4

Two atoms are said to be isotopes if

  1. they have the same atomic number but different mass numbers
  2. the sum of the number of protons and neutrons is the same, but the number of protons is different
  3. they have the same number of neutrons but different modes of radioactive decay
  4. they have the same number of neutrons but different mass numbers
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5

The number of aluminium ions present in 54 g of aluminium (atomic weight 27) is

  1. 2
  2. 18
  3. 1.2 x 1024
  4. 1.1 x 1024
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6

Which one of the following is the correct electronic configuration of chlorine

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

The most of the mass of the atom can be found in

  1. nucleus
  2. electron cloud
  3. charges
  4. electrons
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8

The number of valence electrons in the O2- ion is

  1. 4
  2. 6
  3. 8
  4. 10
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9

How many grams of MgCO3 contain 24.00 g of oxygen? (The molar mass of MgCO3 is 84.30 g mol–1)

  1. 42.15 g
  2. 84.30 g
  3. 126.00 g
  4. 154.00 g
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10

Which one of the following is the correct electronic configuration of chlorine

  1. 7, 8, 2
  2. 2, 8, 7
  3. 2, 8, 8
  4. 2, 7, 8
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11

The distribution of electrons into different orbits of an atom, as suggested by Bohr, is

  1. 2 electrons in the K-orbit, 8 electrons in the L-orbit, 32 electrons in the M-orbit
  2. 2 electrons in the K-orbit, 8 electrons in the L-orbit, 16 electrons in the M-orbit
  3. 2 electron in the K-orbit, 6 electrons in the L-orbit, 18 electrons in the M-orbit
  4. 2 electrons in the K-orbit, 8 electrons in the L-orbit, 18 electrons in the M-orbit
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12

How much CO2 is produced on heating of 1 kg of carbon?

  1. 11/3 kg 
  2. 3/11 kg
  3. 4/3 kg
  4. 3/4 kg
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13

The compound C6H12O4 contains

  1. 22 atoms per mole
  2. twice the mass percent of H as compared to the mass percent of C
  3. six times the mass percent of C as compared to the mass percent of H
  4. thrice the mass percent of H as compared to the mass percent of 0
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14

The ionization energy of hydrogen atom in the ground state is

  1. 13.6 MeV
  2. 13.6 eV
  3. 13.6 Joule
  4. Zero
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15

Electron emission from a metallic surface by application of light is known as

  1. Thermionic emission
  2. Photoelectric emission
  3. High field emission
  4. Autoelectronic emission
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16

The first model of an atom was given by

  1. N. Bohr
  2. E. Goldstein
  3. Rutherford
  4. J.J. Thomson
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17

Elements with valency 1 are

  1. always metals
  2. always metalloids
  3. either metals or non-metals
  4. always non-metals
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18

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
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19

In the Thomson’s model of atom, which of the following statements are correct?

  1. the mass of the atom is assumed to be uniformly distributed over the atom
  2. the positive charge is assumed to be uniformly distributed over the atom
  3. the electrons are uniformly distributed in the positively charged sphere
  4. the electrons attract each other to stabilise the atom

Select the correct option:

  1. (i), (ii) and (iii)
  2. (i) and (iii)
  3. (i) and (iv)
  4. (i), (iii) and (iv)
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20

Which of the following statements about Rutherford’s model of atom are correct?

  1. considered the nucleus as positively charged
  2. established that the α–particles are four times as heavy as a hydrogen atom
  3. can be compared to solar system
  4. was in agreement with Thomson’s model

Select the correct option:

  1. (i) and (iii)
  2. (ii) and (iii)
  3. (i) and (iv)
  4. only (i)
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21

Dalton’s atomic theory successfully explained

  1. Law of conservation of mass
  2. Law of constant composition
  3.  Law of radioactivity
  4. Law of multiple proportion

Select the correct option:

  1. (i), (ii) and (iii)
  2. (i), (iii) and (iv)
  3. (ii), (iii) and (iv)
  4. (i), (ii) and (iv)
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22

The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?

  1. 3115 X
  2. 3116 X
  3. 1615 X
  4. 1516 X
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23

Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in to discovery of

  1. Electron
  2. Proton
  3. Nucleus in the atom
  4. Atomic mass
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24

Which of the following correctly represent the electronic distribution in the Mg atom?

  1. 3, 8, 1
  2. 2, 8, 2
  3. 1, 8, 3
  4. 8, 2, 2
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25

3.42 g of sucrose are dissolved in 18 g of water in a beaker. The number of oxygen atoms in the solution are

  1. 6.68 × 1023
  2. 6.09 × 1022
  3. 6.022 × 1023
  4. 6.022 × 1021
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26

Which of the following correctly represents 360 g of water?

  1. 2 moles of H2O
  2. 20 moles of water
  3. 6.022 × 1023 molecules of water
  4. 1.2044 × 1025 molecules of water

Select the correct option:

  1. (i)
  2. (i) and (iv)
  3. (ii) and (iii)
  4. (ii) and (iv)
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