Download Niels Hedrik David Bohr

 Meyer 1 Niels Henrik David Bohr was born on October 7, 1885 in Copenhagen Denmark. He was the son of Christian Bohr, who was a professor of physics at Copenhagen University, where Niels eventually studied. Niels Bohr’s mother also came from a distinguished family in the science community. Niels had one brother, Harald Bohr, who, like Niels, was a very intelligent person and later became a professor of mathematics. Niels Bohr attended Copenhagen University in 1903 where he studied physics. He received his Master degree in 1909 and his Doctorate degree in 1911 from Copenhagen University. While at the university he studied under Professor C. Christiansen, a brilliant mind in the physic’s world. In college Niels also played for the school’s soccer team. Niels Bohr married his wife Margrethe Norlund in 1912. Together they had six sons, but only four survived to adulthood. After receiving his Doctorate, Niels Bohr traveled to Cambridge, England where he worked with J.J. Thompson. While in England, J.J. Thompson introduced him to Ernest Rutherford, who won the Nobel Prize in 1908 for his discovery of an atom’s nucleus. Bohr worked with Rutherford and began researching atoms and their structure. Bohr combined Rutherford’s idea of an atom’s structure with Max Planck’s quantum theory, put forth in 1901, and came up with his atomic theory. Niels Bohr’s atomic model has an atom’s nucleus in the center of an atom with electrons orbiting around it. The electrons orbit around the nucleus in fixed orbits based on the energy the electrons contain. Electrons can jump orbits either closer or farther from the nucleus. For an electron to jump to an orbit farther from the nucleus the electron must absorb energy, and for an electron to jump to an orbit Meyer 2 closer to the nucleus it must emit energy. This model has been researched and improved a little, but this model is the base of atomic structure as it is known today. For his work Niels Bohr received a Nobel Prize in 1922. After receiving his Nobel Prize, Bohr returned to Denmark where he became a professor of physics at Copenhagen University. While teaching at Copenhagen in 1920 he founded the Institute of Theoretical Physics. Bohr was the director of this institute for the rest of his life. Bohr began to research nuclear physics and had a break through in 1936. Bohr came up with the Liquid-­‐Drop Model explaining how the nuclei of atoms behave. His theory says that an atom’s nucleus behave like the molecules in a drop of liquid. If force is exerted on a nucleus of an atom its protons and neutrons are distorted into a dumbbell shape until, eventually, the nucleus splits along the neck of the dumbbell shape into two equal fragments and release energy. After Hitler rose to power in Germany, Bohr’s Institute in Denmark became a safe haven for Jewish scientists fleeing Germany to stay and continue their research. However when Germany invaded Denmark, Bohr and his family fled to Sweden and eventually to the United States of America. After getting to America Niels and his son Aage, a physicist like his father, joined a group of physicist to work on the Manhattan Project, who’s focus was creating an atomic bomb. Bohr’s Liquid-­‐Drop Model was a main idea that surrounded the idea of an atomic bomb. While doing research in Nevada Bohr had concerns about the power the bomb would have and how it would be used. Bohr became an advocate for communications between nation about the power this weapon has, but was resisted by Winston Churchill and Meyer 3 Franklin Roosevelt. Bohr shared his concerns in his “Open Letter to the United Nation” in 1950, which also called for an “Open world” where countries shared information openly and isolationism was abandoned in order to create a true cultural exchange around the world. In 1954 Bohr helped to establish the European Organization of Nuclear Research. Known as CERN, this organization is a physical research facility that houses many research experiments that require international research and communications between nations. In this space many scientific discoveries have been made by the corroboration of scientists around the world. The next year, in 1955, Bohr helped set up the Atoms for Peace Conference, which took place in Geneva, Switzerland. The conference’s main focus was on peaceful uses for atomic energy, and it was attended by important people from countries all around the world. In 1957 Bohr received the first Atoms for Peace award for his work to find safe and responsible ways to use atomic energy. Bohr was also a leading researcher in Quantum theory. From 1933 to 1962 Bohr wrote numerous articles that focused on the concept of complementarily. This idea says that an electron can be looked at as either a particle or a wave, but not both at the same time. This idea stems from the ability of the measurement device. These devices can only measure an electron as a particle or wave, but can’t simultaneously measure both. The measurements of an electron as a particle or wave are complementary to each other. Niels Bohr spent the last years of his life in Copenhagen and died from a stroke on November 18, 1962. His final work was published unfinished after his Meyer 4 death, but included a look at molecular biology, titled “Light and Life Revisited”. For his work and attributions to the scientific world, the element bohrium was named after Niels Bohr. Meyer 5 Works Cited Palermo, Elizabeth, “Niels Bohr: Biography and Atomic Theory”, livescience.com, May 14 2013, web, Feb. 24 2014 <http://www.livescience.com/32016-­‐niels-­‐
bohr-­‐atomic-­‐theory.html> "Niels Bohr -­‐ Biographical". Nobelprize.org. Nobel Media AB 2013. Web. Feb. 24 2014<http://www.nobelprize.org/nobel_prizes/physics/laureates/1922/bo
hr-­‐bio.html> “Niels Bohr – Biography” , Pbs.org, People and Discoveries, 1998, web, Feb. 24 2014, < http://www.pbs.org/wgbh/aso/databank/entries/bpbohr.html> “Niels Bohr”, Biography.com, people, 2014, web, Feb. 24 2014, .
<http://www.biography.com/people/niels-­‐bohr-­‐21010897?page=2> “Bohr Atomic Model”, Abyss.edu, unknown, web, Feb 24 2014, <http://abyss.uoregon.edu/~js/glossary/bohr_atom.html> “Liquid-­‐drop model”, Britannica.com, Encyclopedia Britannica, Feb. 24 2014, .
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