NIELS HENDRIK 1885 DAVID BOHR 1962 CREATED BY

NIELS HENDRIK 1885 DAVID BOHR 1962

CREATED BY : Sarah Keesee Lauren Le. Gardye Karli Weiand

Niels Bohr Timeline (10/07/1885 -11/18/1962) 1903 entered 1913 completed Copenhagen theory of the atom(Bohr University model) Born Copenhage n, Denmark October 1885 1908 -1911 won gold medal and earned doctorate degree. 1922 wins Nobel Prize for Physics and structure of atoms 1916 appointed to chair of Physics at CU November 18, 1962 died of a stroke 1962 returned to Copenhagen to study nuclear energy

BIOGRAPHY *Bohr was born on October 7 th, 1885 in Copenhagen, Denmark. *He died on November 18 th, 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 LEVELS o. Bohr created many theories on the atomic energy levels and soon created the atomic model based off of these theories. o. Even though his model was incorrect it was very approximate to the correct model. o. This model was called the Quantum model. o. Bohr created the drive to explore more about the atomic models and theories. o. The 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. o. This is often associated with that of the solar system, but instead the model

BOHR’S ENERGY LEVELS EQUATION q. Bohr’s energy level equation is as followed:

ENERGY LEVELS DIAGRAM http: //chemistry. tutorvista. com/i norganic-chemistry/niel-bohratomic-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 DRAWN §Created 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/8 k 7 zg 2_aojw 2/niels-bohr-timeline/ • http: //www. britanniea. com/EBchecked/topic/71670/Niels-Bohr • http: //chemistry. tutorvista. com/inorganic-chemistry/niel-bohr-atomictheory. html • http: //www. mirror. co. uk/news/uk-news/niels-bohr-10 -things-you 1365579#ixzz 3 D 1 XGj. VVl • http: //chemed. chem. purdue. edu/genchem/history/bohr. html • AP Chemistry Book