Chemistry - Atomic Structure and Periodic properties of Elements

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Question - 1

Given atomic mass of silver = 107.87. The mass of silver atom atom would be

  • A 1.79 X 10-24
  • B 1.79 X 10-22
  • C 1.79 X 10-21
  • D 1.79 X 10-20

Question - 2

If international atomic mass of magnesium is 24.3, the mass of one atom of magnesium would be

  • A 1.66 X 10-24 g
  • B 40.34 X 10-24 g
  • C 16.6 X 10-24 g
  • D 4.03 X 10-24 g

Question - 3

Atomic mass of an element is not necessarily a whole number because it contains

  • A allotropic forms
  • B protons and neutrons
  • C indivisible atoms
  • D isotopes

Question - 4

Carbon occurs as a mixture of \(_{ 6 }^{ 12 }C\) and \(_{ 6 }^{ 13 }C\). The atomic mass of \(_{ 6 }^{ 12 }C\) is exactly 12 amu by definition and the atomic mass of  \(_{ 6 }^{ 13 }C\) is 13.003 amu. If the average atomic mass of carbon is 12.001 amu, the atom percent of \(_{ 6 }^{ 12 }C\) in natural carbon would be

  • A 99.2
  • B 98.9
  • C 94.6
  • D 99.0

Question - 5

The line spectrum observed when electrons fall from higher quantum levels to L level is referred to as

  • A Balmer series
  • B Lyman series
  • C Paschen series
  • D Brackett series

Question - 6

Given the electronic configuration 1s2, 2s2, 2p3 the number of unpaired electyrons in the atom is

  • A 0
  • B 1
  • C 3
  • D 7

Question - 7

A subshell with l=3, can take up the maximum number of electrons as

  • A 10
  • B 8
  • C 12
  • D 14

Question - 8

A d-orbital can accomodate electrons up to

  • A two
  • B ten
  • C six
  • D fourteen

Question - 9

Bohr radius of nth orbit of an atom is given by the expression

  • A \(\quad r=\frac { { n }^{ 2 }{ h }^{ 2 } }{ 4{ \pi }^{ 2 }mZ{ e }^{ 2 } } \)
  • B \(\quad r=\frac { { n }^{ 2 }{ h }^{ 2 } }{ 4{ \pi }^{ 2 }mZ{ } } \)
  • C \(\quad r=\frac { { n }^{ 2 }{ h }^{ 2 } }{ 4{ \pi }^{ 2 }m{ e }^{ 2 } } \)
  • D \(\quad r=\frac { { n }^{ }{ h }^{ } }{ 4{ \pi }^{ 2 }m{ e }^{ 2 } } \)

Question - 10

The line spectra are the characteristics of

  • A atoms in the excited state
  • B atoms in ground state
  • C molecules in the excited state
  • D molecules in ground state