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WELCOME

S.N.T.CSREEKANDESWARAM

POOCHAKKALB.Ed 2013-2014

KERALA UNIVERSITY

Submitted by: Safiya k mohamedPhysical science

Reg no: 133 83 019

SUBMITTED TO : Linimol miss,

Physical science

Power point presentation on“BOHR ATOM MODEL”

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: =7Atomic no: =3So, no: of electrons= 3Protons = 3Neutrons =4

CONCLUSIONThus Neils bohr had developed a

simple and scientific way to express the structure of atom by

his Bohr model.