ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

When 6s orbital is complete then next electron goes to

• 6p A
• 6d B
• 5d C
• 4f D

If the value of principal quantum number is 3. the total possible values for magnetic quantum number will be

• 1 A
• 4 B
• 9 C
• 12 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

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

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

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

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

The experimental evidences for the existence of atomic nucleus comes from:

• Line spectrum of hydrogen. A
• Magnetic bonding of cathode rays. B
• Millikan oil drop experiment. C
• Scattering of alpha particles by thin metal foil. 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 particles has longest wavelength, if they have same speed:

• Proton. A
• Neutron. B
• Electron. C
• Positron. D

In the atomic emission spectrum the lines which appear bright, appear dark in absorption spectrum because

• The radiations emitted in emission spectrum are absorbed in absorption spectrum A
• Atomic emission spectrum is continuous B
• Atomic absorption spectrum is continuous C
• Distance between the lines increases D

An electron with n = 3 , l = 2 will be in the sub-shell

• 3p A
• 3d B
• 3f C
• 3s D

In which of the following pairs, the numbers of electrons in the outermost shell are different?

• As,Sb A
• Ge,Sn B
• In,pt C
• Se,Te D

Splitting of spectral lines of the hydrogen atom under the influence or magnetic field is called

• Stark effect A
• Zeeman effect B
• Compton effect C
• Photoelectric effect D

Which of the atoms has 1s², 2s², 2p_x²2p¹_y2p¹_zconfiguration

• Nitrogen A
• Carbon B
• Fluorine C
• Oxygen D

The range of visible spectrum is

• 300 - 600 nm A
• 600 - 900 nm B
• 400 - 750 nm C
• 100 - 300 nm D

The arrangement of subshells in the ascending order of their energy on complete filing of 4f subshell the entering electrons goes to

• 5s A
• 5p B
• 5d C
• 5f D

Which have better penetrating power

• Alpha rays A
• Beta rays B
• Gamma rays C
• X-rays 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 nature of the positive rays depend on

• The nature of the electrode A
• The nature of the discharge tube B
• The nature of the residual gas C
• All of the above D

Balmer's series is in ______ region

• Visible A
• U V B
• I. R. C
• None D

For principle quantum number n=4, the total number of orbitals having l = 3 is

• 3 A
• 7 B
• 5 C
• 9 D

The credit of discovering neutron goes to

• Rutherford A
• Langmuir B
• Chadwick C
• Austen D

Orbitals having same energy are called

• Hybrid orbitals A
• Valence orbitals B
• Degenerate orbitals C
• D-orbitals D

Mass of simple electron is:

• 9.1 x 10^-31 kg

  A

• 9.1 x 10^-30 kg

  B

• 1.66 x 10^-31 kg

  C

• 9.1 x 10^-31 kg

  D

Rutherford's experiment led to the discovery of

• Nucleus A
• Electron B
• Proton C
• alpha particle D

When cathode rays strike the anode metal X-rays are emitted and not the positive rays because

• Cathode rays are material particles A
• Cathode rays knock out electrons from anode, which emit X-rays when outer electron take their place B
• Cathode rays are absorbed by the nucleus C
• Cathode rays become heated D

The total number of orbitals possible for the quantum number n is

• n A
• n² B
• 2n C
• 2n² D

• s A
• p B
• d C
• f D

Effective magnetic moment of Sc³⁺ion is

• 1.73 A
• 0 B
• 5.92 C
• 2.83 D

Which of the following has more unpaired d-electrons?

• Zn⁺ A
• Fe²⁺ B
• Ni³⁺ C
• Cu⁺ D