Branches of science which explain duel behavior of Metter is called quantum mechanics.It contradicts Heisenberg’s uncertainty principle. It ignores the dual behavior of matter.Ģ. Reasons for the Failure of the Bohr Model:ġ. The effect of Heisenberg Uncertainty Principle is significant only for motion of microscopic objects and is negligible for that of macroscopic objects.Heisenberg’s uncertainty principle rules out the existence of definite paths or trajectories of electrons and other similar particles.The product of their uncertainties is always equal to or greater than h/4π. It states that it is impossible to determine simultaneously, the exact position and exact momentum (or velocity) of an electron. The above equation is named as de Broglie’s relation. It failed to explain splitting of the spectral lines in presence of electric (Stark effect) or magnetic field ( Zeeman effect).Ĥ. It failed to explain formation of molecules from atoms by chemical bonding.ĭe Broglie proposed that matter exhibits dual behavior, i.e., matter shows both particle as well as wave nature and gave the following relation between wavelength (λ) and momentum ( p) of a material particle. It was unable to explain spectrum of atoms containing more than one electron.ģ. It failed to account for the finer details of the hydrogen spectrum.Ģ. Energy of an electron in nth orbit is given as:ġ. The radii of the stationary states are expressed as:Ģ. Some more assumptions of Bohar’s model are:ġ.

Cbse class 11 chemistry notes