ECAT Pre Engineering Chemistry Chapter 5 MCQ Test With Answer

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

The value of R (Rydberg's constant) is _______ m-1

• 1.0974 x 107 A
• 1.0842 x 107 B
• 1.082 x 10-7 C
• Both a and b D

Light emitted from a source has its wave length 500nm, then its wave number will be

• 2 x 10⁶m^-1 A
• 2 x 10⁷m^-1 B
• 5 x 10⁸ m^-1 C
• 5 x 10⁹m^-1 D

Cathode rays drive a small paddle wheel placed in their path. This observation shows that

• Cathode rays travel in straight lines A
• Cathode rays are negatively charged B
• Cathode rays produce x-rays C
• Cathode rays are material particles having momentum 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 of the following has more unpaired d-electrons?

• Zn⁺ A
• Fe²⁺ B
• Ni³⁺ C
• Cu⁺ D

Which of the following is not a sub-atomic particle

• Electron A
• Proton B
• Neutron C
• Deuteron 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

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

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

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

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

Proton was discovered by:

• Chadwick A
• J.J. Rhomson B
• Millikan. C
• Goldstein. 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

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

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

Photons of yellow colour are ______ energetic than violet colour

• More A
• Less B
• Equal C
• None 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

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

• 7f. A
• 7s. B
• 7p. C
• 7d. D

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

• N A
• Li B
• P C
• Na D

Neutron was discovered by:

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

Which is not true with respect to cathode rays?

• A stream of electrons A
• Charged particles B
• Move with speed as that of light C
• Can be deflected by magnetic fields D

The nature of positive ray depend on:

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

• s A
• p B
• d C
• f D

Orbitals having same energy are called

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

Schrodinger wave equation describes electron completely because

• It describes a set of four quantum number A
• It describes the particle nature of electron B
• It measures wavelength of electron C
• It describes electron moving in specific orbit D

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

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

The size of electronic shell is described by

• Azimuthal Q. no A
• Magnetic Q.No B
• Spin Q. No C
• Principle Q. No D

An orbital can accommodate maximum two electrons with opposite spins according to

• Heisenberg's principle A
• Aufbau principle B
• Hund's srule C
• Pauli exclusion principle 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

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

Which of the following is not charged particle

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