NIELS HENRIK DAVID BOHR Contribution to Atomic Theory

NIELS HENRIK DAVID BOHR • Physicist, scientist, humanitarian, and mathematician • Born October 7, 1885 • From Copenhagen, Denmark • Died November 18, 1962 • Father was celebrated physicist • Studied at University of Copenhagen • Won 1922 Nobel Peace Prize in physics

NEILS BOHR’S CONTRIBUTION TO THE ATOMIC THEORY Dates of Importance

1913 • Neil completed the Bohr Model - This model proposed that electrons circled the atom’s nucleus in a certain way, therefore it also explained that electron traveled in specific energy. - The model also purposed that electrons could drop from higher energy orbit to a lower orbit. Also showed the light quantum of distinct energy, which formed the bases for the quantum theory. - Quantum theory showed the specific relation proportion of an electron and how it circulates the atoms’ nucleus

1922 • Bohr received a Nobel Prize in Physics for work of "for his services in the investigation of the structure of atoms and of the radiation emanating from them. " • He continued to study new quantum principles which ultimately explained why light can be seen as a particle and wave but not at the same time • He developed an explanation for atomic structure that uses the periodic table of elements.

1930 • Neil clarified problems in quantum physics • Work on nuclear fission and created liquid droplet theory which described the way neutrons and protons behaved.

1950’S • In 1954 , Neil assembled the Atoms for Peace Conference of 1955. • In 1957, Bohr received the Atoms for Peace Award for his theories and examples to show to use atomic energy responsibly. 1962 • Returned to Copenhagen and furthered studied nuclear energy.

NIELS BOHR And the Atomic Theory

THE BOHR MODEL • The Bohr Model of the atom revealed some of the most important properties of molecular and Atomic structure. • The Bohr model gave way to theory of Atoms, which is called Quantum mechanics. • Model was brought up in 1913. • Electrons orbit around the nucleus which contains the Neutrons and Protons. • Proposed that Atoms moved In fixed paths around the nucleus, like planets orbiting a sun.

Bohr’s model continued… • Bohr concluded that the outer orbits could hold more electrons than the inner ones. • He also concluded that these outer orbits can determine an atom's chemical properties, and that Atoms emit radiation and light when an electron jumps from an outer orbit to an inner one. • Later other physicists expanded his theory into quantum mechanics. Which explains the structure and complexity in the actions of atoms.

Bohr’s Experimental Procedures • Using the Young’s slit device, Bohr delimited two quantum paths between the source and the detecting plane. • Bohr composed an accurate formula for the energy levels of a hydrogen atom using Planck’s constant. He hypothesized that the angular momentum of the electron is quantized (which means it only has discrete values). He concluded that because of this quantization, electron orbits have fixed sizes and energies. • The orbits are labeled by the quantum number n.

NEILS BOHR: CONTRIBUTIONS TO THE ATOMIC THEORY Will Westenberger Jhace Smith Tiphani Cohens Samantha Silva-Nash

ANALYSIS AND CONCLUSION FROM HIS EXPERIMENT This Bohr model, a quantum model shows that hydrogen absorbs light when an electron moves from one energy level to another. The electron can move from a low energy orbit to a high energy orbit and give off light or the electron can move from a high energy orbit to a low energy orbit and give off light. The light comes from the electric discharge that is created by the atoms that have moved. For example when an electron goes from a low energy orbit such as n=1 to n=7 the atoms that have been moved by an electric discharge can give off light when the electrons move to the higher energy orbit. A real life example would be a neon light, when the neon gas has electricity added to it the electrons shift around causing atoms to move which gives off the neon light. http: //www. neonsignworld. co m/neon_lights. htm

NEILS BOHR QUOTES • "Never express yourself more clearly than you are able to think. “ • "Every great and deep difficulty bears in itself its own solution. It forces us to change our thinking in order to find it. " • "Everything we call real is made of things that cannot be regarded as real. “ • “No, no, you're not thinking; you're just being logical. ”