Transcript Niels Bohr Presentation

Niels Bohr and Atomic
Energy Levels
By Nina Sellers and Shelby Cramer
Niels Bohr: A Biography
●Full name: Niels Henrik David Bohr
●Born October 7th, 1885
●Died November 18th, 1962
●Born in Copenhagen, Denmark
Niels Bohr: A Biography
●Went to many different schools, including Gammelholm
Latin School, and Copenhagen University
●Danish Physicist; studied under Christian Christiansen,
the only physics professor at the time
●Also studied mathematics and astronomy
●Known for the Bohr model
Most Important Work
Helped contribute to the understanding of the structure of an
atom and quantum theory
●
In order to graduate, he wrote an important thesis on the
electron theory of metals
●
In 1921, the Dutch physicist Hendrika Johanna van Leeuwen
would independently derive a theorem from Bohr's thesis that is
today known as the Bohr-van Leeuwen theorem
●
He read into it, and eventually decided on a model by Paul
Drude and elaborated by Hendrik Lorentz. The model
demonstrated how electrons in a metal seem like a gas
●
The Bohr Model of the Atom
●
Electron's energy levels in the atom:
to find the electron capacity, the formula is 2n^2
●
The variable n represents the number of the energy level
Most Important Work (cont'd.)
● Despite his research and overall knowledge on the topic,
he failed to explain the Hall Effect (the voltage difference
made across a conductor of electricity)
● Concluded that his theory failed to explain other metal's
magnetic properties
● Since his these was written in Dutch, it was not
understood by many outside of Scandinavia
● Even with this setback, it was still a groundbreaking event
for science
Why it's important
● He adapted Rutherford's nuclear structure to Max
Planck's quantum theory and so created his Bohr Model
of the atom.
● Energy levels (discrete)
● Introduced the idea of electrons being able to drop into
a lower-energy orbit from a higher one, and whilst
doing this, give off a quantum of discrete energy
● This was the basis for the old quantum theory
Importance of Atomic Spectra
●
Substances that are not known can now be known by adding
heat and observing the specific frequency of light that is
emitted
●
Light can also be shown onto them to see the frequencies
that are absorbed
●
This can be applied to analyze any substance (even elements
that are in space and planets!)
Why it's important (cont'd)
● Without Bohr's experiments and his insight on atomic
energy levels, our understanding of atoms (in general and
their charges) would be minimal
● Due to his diagram and discovery of the atom, big
advances in technology were able to be made
Bohr's Involvement
● Involvement in development of atomic theory:
– Due to his breakthrough with the understanding of the
atom, he inadvertently helped with the atomic bomb in
the Manhattan Project (as did others like Einstein)
– Made theories about the structures of atoms and
through models and research proved what was soon to
be a breakthrough
– The Bohr Model of atomic structure was the
core of all future theories regarding quantum
mechanics
Pictures
The Bohr model of
the Hydrogen Atom
● Negatively charged
electron orbits a small
positively charged
nucleus
● Quantum jump between
orbits with help from an
absorbed amount of
electromagnetic
radiation