NIELS BOHRWas a Danish physicist who made foundational contribution to atomic structure and quantum theory for which he received the Nobel price in physics
BOHR MODEL According to the Bohr model of atom, Electrons are revolves around the nucleus in certain discrete paths called “ORBITS”
In atom electrons are present around the nucleus in shells • Each shell have a particular amount of energy, so shells are called energy levels • The shell which is more close to the nucleus have low energy, when the distance increases energy also increases. • In bohr model 1st, 2nd,3rd,4th,5th energy levels are known as K,L,M,N,O shells respectively.
Atomic number & Mass number The number of protons in an atom is called its atomic number(Z). Atomic number = no: of protons = no: of electrons The total no: of particles in the nucleus is called mass number (M). It is the sum of the no: of protons and neutrons. Mass number + no: of protons + no: of neutrons
Eg: In Lithium, Mass no: =7 Atomic no: =3 So, no: of electrons= 3 Protons = 3 Neutrons =4
CONCLUSIONThus Neilsbohr had developed a simple and scientific way to express the structure of atom by his Bohr model.