NIELS HENDRIK DAVID BOHR

1885-1962

CREATED BY:Sarah KeeseeLauren LeGardyeKarli Weiand

Niels Bohr Timeline (10/07/1885-11/18/1962)

Born Copenhagen, Denmark October 1885

1903 entered Copenhagen University

1908-1911 won gold medal and earned doctorate degree.

1913 completed theory of the atom(Bohr model)

1916 appointed to chair of Physics at CU

1922 wins Nobel Prize for Physics and structure of atoms

1962 returned to Copenhagen to study nuclear energy

November 18, 1962 died of a stroke

BIOGRAPHY*Bohr was born on October 7th, 1885 in Copenhagen, Denmark.

*He died on November 18th, 1962 in Copenhagen, Denmark.

*Bohr had one older brother, Harald who was on the Danish Olympic Soccer Team in 1908.

*When he was younger he had troubles with reading and writing. He struggled so much with writing that he had to get his mother to help him write his thesis for his Ph. D.

BIOGRAPHY CONTINUED*Even though he struggled with reading and writing he was a brilliant physicist and soon came up with a quantum model for the hydrogen atom by the time he was 27.

*Though this model was proven incorrect, he still remained an iconic figure for the drive to understand the atom.

*In 1922 Bohr was awarded the Nobel Prize in Physics for his work on atomic structures.

BOHR’S WORK•Bohr worked on a theory for the hydrogen atom based on quantum theory.

•He worked on the problem on the atom’s structure.

•Bohr based his model off of Rutherford’s theory of the atom.

•His model wasn’t completely correct, but it was very approximate.

•Bohr also worked on theories for energy levels and hydrogen models.

BOHR’S ENERGY LEVELSoBohr created many theories on the atomic energy levels and soon created the atomic model based off of these theories.

oEven though his model was incorrect it was very approximate to the correct model.

oThis model was called the Quantum model.

oBohr created the drive to explore more about the atomic models and theories.

oThe Bohr model showed the atom as a small, positively charged nucleus that was surrounded by elections that orbits in a circular pattern around the nucleus.

oThis is often associated with that of the solar system, but instead the model suggests that the attraction is by elections rather than gravity.

BOHR’S ENERGY LEVELS EQUATIONBohr’s energy level equation is as followed:

ENERGY LEVELS DIAGRAM

http://chemistry.tutorvista.com/inorganic-chemistry/niel-bohr-atomic-theory.html

A model of Niel’s Bohr energy levels

HYDROGEN ATOM BASED ON THESE ASSUMPTIONS..•The electron in a hydrogen atom travels around the nucleus in a circular orbit.•The energy of the electron in an orbit is proportional to its distance from the nucleus. The further the electron is from the nucleus, the more energy it has.

HYDROGEN ATOM BASED ON THESE ASSUMPTIONS.. (CONTINUED)•Only a limited number of orbits with certain energies are allowed. In other words, the orbits are quantized.

•The only orbits that are allowed are those for which the angular momentum of the electron is an integral multiple of Planck's constant divided by 2.

•Light is absorbed when an electron jumps to a higher energy orbit and emitted when an electron falls into a lower energy orbit.

•The energy of the light emitted or absorbed is exactly equal to the difference between the energies of the orbits.

IMPORTANT FACT! Fearing arrest by the Germans, Niels fled to Britain during World War II and then to New Mexico to work on the Manhattan Project - a research and development program by the US and UK - that produced the first atomic bomb!

CONCLUSIONS DRAWNCreated many theories for an atom’s energy levels.Soon many models were made based off of these theories.

Bohr came up with an incorrect, but accurate model of the atom’s energy levels.This created a drive to explore more about atoms and their energy levels.Created an equation to figure an atom’s energy levels.Came up with the Hydrogen atom.

REFERENCES •http://prezi.com/8k7zg2_aojw2/niels-bohr-timeline/

•http://www.britanniea.com/EBchecked/topic/71670/Niels-Bohr

•http://chemistry.tutorvista.com/inorganic-chemistry/niel-bohr-atomic-theory.html

•http://www.mirror.co.uk/news/uk-news/niels-bohr-10-things-you-1365579#ixzz3D1XGjVVl 

•http://chemed.chem.purdue.edu/genchem/history/bohr.html

•AP Chemistry Book