Describe Bohr's model of atom.

Explanation

A Danish physicist , Neils Bohr proposed an atomic model in 1913 . This model of atom is called Bohr.s model of atom .
Basic postulates of the Bohr.s atomic model are :
(i) In an atom the electrons revolve around the nucleus in certain definite circular orbits . These circular orbits are also called energy shells or energy levels .
(ii) An electron revolving in a particular orbit has a fixed energy .
(iii) The orbits , or the energy shells are numbered as n = 1 , 2 , 3 , 4 ...., etc or K , L , M , N .... ,etc , shells starting from the nucleus . These integers 1 , 2 , 3 , 4 , ...etc ., are known as quantum numbers of the orbits .
(iv) An electron can lose or gain only certain definite energies .