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Slide 1

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1885­1962…read more

Slide 2

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Niels Henrik David Bohr was born in Copenhagen on
October 7, 1885, as the son of Christian Bohr, Professor of
Physiology at Copenhagen University.
His father was an eminent physiologist and was largely
responsible for awakening his interest in physics while still
at school. Bohr's activities in his Institute were since 1930
more and more directed to research on the constitution of
the atomic nuclei. In 1936 he pointed out that in nuclear
processes the smallness of the region in which interactions
take place, as well as the strength of these interactions,
justify the transition processes to be described more in a
classical way than in the case of atoms.…read more

Slide 3

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Neils Bohr postulated based on quantum
theory that electrons travel around an atomic
nucleus in a stationary orbit. His work also led
to the theory of different energy levels in
atoms, that is if an electron drops from a
higher to a lower orbit, it must release
According to the model, the nucleons
(neutrons + protons) behave like the molecules
in a drop of liquid. If given sufficient extra
energy (as by the absorption of a neutron), the
spherical nucleus may be distorted into a
dumbbell shape and then split at the neck into
two almost equal fragments, then releasing
energy. Although inadequate to explain all
nuclear phenomena, the theory underlying the
model provides excellent estimates of average
properties of nuclei. This so-called liquid
droplet theory permitted the understanding of
the mechanism of nuclear fission.…read more

Slide 4

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A child jumping down stairs also behaves somewhat like an electron
changing states within an atom. In this case, she gives off energy to the
floor as she jumps to a lower stair or state. But Bohr realized, like Planck
and Einstein, that this energy can only come in chunks or quanta. A jump
from step four to step two gives off two steps' worth of energy or a jump
from step five to step two gives off three steps of energy.
An electron jumping to a lower state gives off its energy in the form of
light. A jump from orbit or step five to orbit three might radiate quanta
of red light; a jump from six to two might radiate more energy (higher
frequency), so it could be a blue light. In terms of other types of
electromagnetic radiation, a jump from orbit one to the ground might
give off low energy radio waves, while a jump from orbit eight to the
ground might give off high energy x-rays. This then was the way that Bohr
described the quantum leap and how light was emitted.…read more

Slide 5

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Neils Bohr is considered the
grandfather of quantum mechanics.
Grandfather Bohr…read more

Slide 6

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S In Physics (1922)
Nobel Prize
Franklin Medal (1926)…read more

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