ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

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

• N A
• Li B
• P C
• Na D

The radius of second Bohr's orbit is

• 0.053 nm A
• 0.053/4 nm B
• 0.053 x 4 nm C
• 0.053 x 20 nm D

Rutherford's model of atom failed because:

• The atom did o have a nucleus and electrons A
• It did not account fro the attraction b/w protons and neutrons B
• It did no account for the stability of the atom. C
• There is actually no space b/w the nucleus ad the electrons. 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 number of de-electrons retained in Fe²⁺ (At.No. of Fe = 26) ions is

• 3 A
• 4 B
• 5 C
• 6 D

E = hv is the

• Spectral equation A
• Plank's equation B
• de Broglie's equation C
• None of these 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

Charge to mass ratio of electron was discovered by:

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

Negatively charged particle nature of cathode rays was first demonstrated in 1895 by:

• Millikan. A
• J. Perrin. B
• Hittrof C
• J.J. Thomson. D

Which one of the following particles has amass 1/1836 time, that of hydrogen?

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

Which of the following particles has longest wavelength, if they have same speed:

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

Which of the following is not charged particle

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

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

• 4s A
• 3d B
• 4p C
• 4f D

Splitting of spectral lines when atoms are subjected to strong electron field is called

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

The atomic number of an element is 35 what is the total number of electrons present in all the p-orbitals of the ground state atom of that element?

• 6 A
• 11 B
• 17 C
• 23 D

Splitting of spectral lines when atoms are subjected to strong electric field is called:

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

Neutron was discovered by:

• Chadwick. A
• Bohr. B
• Rutherford. C
• Plank. D

Which of the following is not a property of cathode rays

• They can produce x-rays when they strike a heavy metal anode A
• They can cause reduction reaction B
• They produce fluorescence in rare earth and minerals C
• They comprise neutral particles 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 electronic configuration of an atom/ion can be defined by the following

• Aufbau principle A
• Pauli's exclusion principle B
• Hund's Rule C
• All the above D

A 4f orbital has

• one node A
• two node B
• three node C
• four nodes D

The correct set of quantum numbers (n,l and m) respectively of the unpaired electron of chlorine atom is

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

If the radius of first Bohr orbit be a_o, then the radius of third Bohr orbit would be

• 3 x a_o A
• 6 x a_o B
• 9 x a_o C
• 1/2 x a_o D

Charge on electron was discovered by:

• Millikan. A
• Crook. B
• Neil Bohr. C
• Rutherford. 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

Balmer's series is in ______ region

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

Which of the following is not isoelectronic?

• Na⁺ A
• Mg²⁺ B
• O^2- C
• Cl^- D

• Plank's equations A
• de Broglie's equations B
• Heisenburg's equation C
• None D