ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

The order of distance between the various Bohr orbits is

• r₂- r₁> r₃- r₂> r₄- r₃> ...... A
• r₁> r₂> r₂- r₃> r₄-r₃> ..... B
• r₂-r₁= r₃- r₂= r₄- r₃> ..... C
• r₂- r₁> r₃- r₂< r₄- r₃< .... D

Spectrum of white light is continuous becuase

• Colors separated by dark spaces A
• There are no boundary lines between the colours B
• The radiations are in infrared region C
• The radiatins fall in ultraviolet region D

Which of the following element's outermost orbits last electron has magnetic quantum number m=0?

• Na A
• O B
• Cl C
• N D

The total number of orbitals in a shell with principal quantum number 'n' is

• 2n A
• 2n² B
• n² C
• n + 1 D

The charge over mass ratio of electron is:

• 1.6 x 10^-1 C Kg^-1

  A

• 9.1 x 10^-31 C Kg^-1

  B

• 1.7588 x 10¹¹ C Kg^-1

  C

• 6.62 x 10^-34 C Kg^-1

  D

If the value of azimuthal quantum number is 3, then values of m the magnetic quantum no. will be

• 0, 1, 2, 3 A
• +3, +2, +1, -1, -2, -3 B
• 0, -1, -2 ,-3 C
• -3, 0, +3 D

When 6d orbital is complete, the entering electron goes into:

• 7f. A
• 7s. B
• 7p. C
• 7d. D

When the 6d orbital is completed the entering electron goes into

• 7f A
• 7 s B
• 7 p C
• 7 d D

The quantum number which describes the shape of the orbital is

• Principle quantum number A
• Spin quantum number B
• Azimathal quantum number C
• Magnetic quantum number D

In the ground state, an element has 13 electrons in its M shell. The element is

• Copper A
• Chromium B
• Nickel C
• Iron D

Rutherford's planetary like picture of the atomic modal was defective because

• It did not describe the quantity of positive charge A
• It did not explain the repulsion of protons within the nucleus B
• No empty space between nucleus and the electrons C
• Moving electron should radiate energy D

Which of the following is not charged particle

• Proton A
• Electron B
• Neutron C
• Hydrogen nucleus D

When potassium metal is exposed to violet light

• Ejection of electrons takes place A
• Ejection of some potassium atoms occurs B
• There is no effect C
• The absorption of electrons takes place D

The limiting line of Blamer series in hydrogen spectrum lies in

• Visible regions A
• Ultraviolet region B
• Infrared region C
• x-rays region D

Number of neutrons in heavy hydrogen atom is

• 0 A
• 1 B
• 2 C
• 3 D

The total values of magnetic quantum number of subshell are five, the subshell is

• S-subshell A
• P-subshell B
• D-subshell C
• F-subshell D

When the electron jumps form third, fourth, fifth orbits to the second orbit, the transitions are known as

• Paschen A
• Pfund B
• Balmer C
• Brackett D

Bohr model of atom is contradicted by:

• Planck's quantum theory A
• Pauli's exclusion theory B
• Heisenberg's uncertainty principle. C
• All of above. D

The symbol of the element whose atoms have the outer most electronic configuration 2s²2p³is

• N A
• Li B
• P C
• Na D

Charge to mass ratio of electron was discovered by:

• Millika. A
• Rutherford. B
• J.J. Thomson. C
• Chadwick. D

When 3p orbital is complete, the entering electron goes into

• 4s A
• 3d B
• 4p C
• 4f D

• s A
• p B
• d C
• f D

The radiations with wavelength shorter than violet light are called

• Ultraviolet A
• Infrared B
• Microwave C
• Radio frequency D

Quantum number values for 2p orbitals are

• n = 2, l = 1 A
• n = 1, l = 2 B
• n = 1, l = 0 C
• n = 2, l = 0 D

In Bohr model of hydrogen atom the distance between adjacent orbits increases away from the nucleus, the energy difference between the orbits

• Increases A
• Decreases B
• Reaming same C
• Orbits coincide D

When electrons revolve in stationary orbits

• There is no change in energy level A
• They vecome stationary B
• They are gaining kinetic energy C
• There is increase in energy D

Anode is the surface on which probability of finding electron is:

• 50% A
• Less than 10%. B
• More than 95%. C
• Zero. D

Four d-orbitals contain four lobes while fifth contains only two lobes the orbital is

• dxy A
• dxz B
• dz² C
• dx²- y² D

The valence orbital configuration of an element with atomic number 23 is

• 3d⁵ A
• 3d³, 4s² B
• 3d³, 4s¹, 4p¹ C
• 3d²,4s²,4p¹ D

The wave number of the line emitted is 109.678 x 10⁵m^-1in the Lyman series when electron transition occurs

• 
  A
• 
  B
• 
  C
• 
  D