neils bohr atomic model

PENCHAL REDDY HIGH SCHOOL

CHEMISTRYCHEMISTRYPower Point Presentation

N. BHARGAV SAI 027

N.SHAKEER 030

P. UMA MAHESH 033

A. MOUNIKA 045

About Neils Henry Bohr

Name: Neil Henry Bohr

Year: 1885 – 1962

Country: Copenhegan (Denmark)

Year of Noble Prize: 1922

Bohr's Model of the AtomMain Postulates:

Electrons revolve around the nucleus in a definite circular path called

orbit or shells in an atom.

These orbits or shells called Energy Levels or Energy Shells. These are

designated by letters, K,L,M,N. The Energy of orbits closest to nucleus has lowest energy & Farthest

away from the nucleus has highest energy.

Bohr's Model of the Atom Energy of electron remains constant. So, these shells are also called

Stationary States. Electrons moves from lower energy level to higher energy level by

absorbing energy.

Electrons moves from higher energy level to lower energy level by

losing energy.

Bohr's Model of the Atom

Nucleus

Electron

Orbit

Energy Levels

Bohr's Model of the Atom

Bohr's Model of the Atom

Bohr's Model of the Atom

Bohr's Model of the Atom

Electrons orbit the nucleus like planets orbit the sun.

Each orbit can hold a specific maximum number of electrons.

Bohr's Model of the Atom

The theory could not account for the spectra of atoms more complex than

hydrogen.

The theory does not give any information regarding the distribution and

arrangement of electrons in an atom.

It doesn't explain, the experimentally observed variation in intensity of the

spectral lines of the element.

Bohr's theory could not account for the fine structure of spectral lines.

Bohr's theory could not explain the Stark and Zeeman effects.

1. https://en.wikipedia.org/wiki/Bohr_model2. http://images.tutorvista.com/cms/images/81/neils-bohr-model-atom1.png3. https://upload.wikimedia.org/wikipedia/commons/1/17/Bohr_atom_animation_2.gif5. http://abyss.uoregon.edu/~js/glossary/bohr_atom.html 6. Saraswati Chemistry Text book of 9 CBSE.

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Alpha particle

Large angle of deflection, must have hit massive object!

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Gold Atom

Thank you