Chemistry Class-11: Chapter –2. Structure of Atom – Part-6

Get top class preparation for JEE/Mains Chemistry right from your home: fully solved questions with step-by-step explanation- practice your way to success.

III Short Answer Type

Question: 31

The electronic configuration of valence shell of Cu is 3d104s1 and not . How is this configuration explained?


Completely filled and half-filled orbitals have extra stability. In orbital is completely filled and s is half filled. So it is more stable configuration.


The Balmer series in the hydrogen spectrum corresponds to the transition From This series lies in the visible region. Calculate the wave number of line associated with the transition in Balmer series when the electron moves to orbit.


For transition in Balmer series


According to de Broglie, matter should exhibit dual behavior, that s both particle and wave like properties. However, a cricket ball of mass does not move like a wave when it is thrown by a bowler at a speed of . Calculate the wavelength of the ball and explain why it does not show wave nature



What is the experimental evidence in support of the idea that electronic energies in an atom are quantized?


Since the wavelength is very small, the wave nature cannot be detected.


Out of electron and proton which one will have, a higher velocity to produce matter waves of the same wavelength? Explain it.


Being lighter particles, electrons will have higher velocity.



A hypothetical electromagnetic wave is shown in Fig. 2.2. Find out the wavelength of the radiation.


Electromagnetic Wave

Electromagnetic Wave

Loading image


Chlorophyll present in green leaves of plants absorbs light at 4.620 × 1014 Hz. Calculate the wavelength of radiation in nanometer. Which part of the electromagnetic spectrum does it belong to?



What is the difference between the terms orbit and orbital?



Table-tennis ball has a mass and a speed of . If speed can be measured within an accuracy of what will be the uncertainty in speed and position?


Uncertainty in the speed of ball

Uncertainty in position .


The effect of uncertainty principle is significant only for motion of microscopic particles and is negligible for the macroscopic particles. Justify the statement with the help of a suitable example.



Hydrogen atom has only one electron, so mutual repulsion between electrons is absent. However, in multielectron atoms mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms?


The energy of electron is determined by the value of n in hydrogen atom and by in multielectron atom. So for a given principal quantum number electrons of s, p, d and f orbitals have different energy.