Neils Bohr has a major contribution towords the structure of atom. He has given Bohr's Bury rules for the distribution of electrons in the various shells in an atom. Apart from that, he has also introduced the concept of ground state and excited states for an electron. But Bohr theory does suffer from certain defects. The present picture of the atom is mainly due to the researches carried by Heisenberg.
(i) State the Heisenberg's uncertainty principle.
(ii) Give its mathemetical form.
(iii) Why does the principle have no utility in daily life ?

Explanation

(i) According to the principle , "it is not possible to measure simultaneously the position and the momentum of a microscopic particle with absolute accuracy".
(ii) `Deltax.Deltap ge h//4pi`.
(iii) A human eye is not in a position to see microscopic particles. Since the principle applies only to the microscopic particles, it has therefore, no utility in daily life.