Transcript PowerPointbohr

Niels Bohr
A Brief History
By: Dusty, Garrett, Jason & Timmay!
Who He Was
• Name: Neils Bohr
• Home: Copenhagen,
Denmark
• Lived: Oct. 7 18851962
• Education: Doctorate
in physics, University
of Copenhagen, 1911
Niels Bohr
• Neils Bohr, a Danish Physicist, developed
many theories about atoms and their
construction during the 19 and 20th century.
This lead to many interesting ideas about
atomic reactions to the presence of energy
and its effects. We still use Bohr’s theories
to explain many occurrences in the world
around us.
Accomplishments
• 1913: Published theory of atomic structure, based
on Rutherford’s pre-existing theory of the atom.
• 1916: Professor of Physics, University of
Copenhagen
• 1920: Named director of the newly constructed
Institute of Theoretical Physics
• 1922: Won Nobel Prize for physics, for his work on
atomic structure
• 1926: He became a Fellow of the Royal Society of
London
• 1938: Received the Royal Society Copley Medal
Development of Theories
Basic Model
Rutherford
Positively Charged Nucleus
Negitivly Charged particles Orbiting Nucleus
Energy Model
Bohr Model 1
Electrons are in different energy levels
(shells) around the nucleus
Energy
changes the orbitals
that electrons are in
Orbitals are sucessively
larger as energy
increases
Energy Model
Bohr Model 2
Electrons being energized jump to next
energy level and fall back
Light is
produced
Spectrum
is evident
Atoms can be
identified by spectrum
color
Different energy
levels exist
Rutherford Model #1
Rutherford Model #2
Bohr’s First Model
The End Of A Long Career
• After perfecting his atomic
model, Bohr continued to study
physics and chemistry keeping
in mind what he and his peers
had discovered about the atom.
Never neglecting new theories
different from his own, Bohr
remained open-minded and
active in the science world.
• After the war he strove to
achieve a society where nuclear
energy could be used to benefit
the world rather than destroy it.
Sadly, he died in 1962.
Article Analysis
Autumn has returned to the Northern Hemisphere, bringing with it longer
nights and more auroral displays. But fall is not the only good season for
sky watchers. Historically, both spring and fall host frequent auroral activity.
While scientists are still figuring out the reasons for this, make sure you take
some extra time this season to check your skies for one of nature's most
beautiful displays.
"We've known about this seasonal effect for more than 100 years," says
Dennis Gallagher of NASA's Marshall Space Flight Center. "Some aspects
of it are understood, but not all."
Aurorae occur when solar particles stream off of the sun and interact
with Earth's magnetic field. We are protected from most of the solar wind
due to Earth's magnetosphere. The sun's magnetosphere extends millions
of miles out into space extending beyond all the planets. The two
magnetospheres bump up against each other at the magnetopause, or the
outer edge of Earth's magnetosphere. Only when a large influx of solar
particles batters the magnetopause do those particles get excited and begin
to glow, beginning at the poles and extending farther down toward the
midlatitudes during large solar storms.
Bohr’s Explanation
“It has been presented to me that particles from the sun, known as
solar wind, float through space and interact with the earth’s
magnetosphere, a magnetic barrier that protects us from solar wind.
Where the sun’s magnetosphere meets with the earth’s, there is
something called a magnetopause. When large amounts of solar wind
meet magnetopause there is a transmission of energy to solar
particles. When energy reacts with these atoms, their electrons
become excited and ‘leap’ from their current energy level to a higher
one. This depends on the amount of energy that is present. The
energy cannot be sustained, therefore, the electrons must fall back to
their previous energy level. This is an obvious change in energy and
the result is seen as light, in multiple frequencies, being emitted.
These frequencies depend on both the amount of energy and the
atoms being affected. We see these different energy levels as
different colours of bright light in the sky known as Aurora Borealis, or
more commonly known as The Northern Lights, due to the latitudes
where they are most brightly seen.” -Based on ideas of Dr. Niels Bohr.