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Models of the Atom
Over the past years there have been many proposed models of the atom by
different scientists over the world. These models tend to have a common factor,
which shows how each model has advanced from the previous one. Famous
atomic models include the Bohr Model, Thomson's Atom and many more.
plays an important part in
the evidence of the
atomic model today. In
discovered the electron.
He proved that these
electrons had a negative
charge around them and
that their mass was much
less than the proposed
atom. Therefore he
believed that the centre
of the atom must have a
positive charge so that the charge of the atom itself would be neutral. Thomson's
model was also referred to as the Plum Pudding model of the atom. However in
1911 this model was banned theoretically and on experimental grounds in favour
towards Rutherford's model of the atom.
Rutherford's model was introduced in 1911. Ernest Rutherford's model built on
Thomson's model with the idea that electrons existed however circulated the
central charge of the
atom, similar to how planets
orbit. The central charge
(today known as the
nucleus) was where the
positive charge of the atom
was contained. This is
where nearly all the mass
Rutherford's model was
also known as the nuclear
atom or the planetary
The Bohr Model depicted the atom to have a small positively charged nucleus
with negatively charged electrons orbiting it.
However Niels Bohr did not use gravity as his
explanation to the stability of the electrons,
however he used `Electrostatic Forces'. This was
an improvement on earlier proposed models
including the Thomson model and Rutherford's
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Model. Bohr's model changed future models largely. The key success to the
model was sought from its success in explaining Rydberg's model for `the
spectral emission lines of atomic hydrogen'. The Bohr model was a success in
explaining the structure of Rydberg's model. The model below shows when
electrons jump between orbits there is electromagnetic energy (hv) emitted.
The BohrSommerfeld model enhanced Bohr's model significantly however
also saw some changes to Bohr's original model.…read more
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Therefore, if this diagram shows a neutral
atom, there would be as many protons as there are electrons.
Therefore we can see from this that there have been many proposed models and
theories of the atom, which have been an important part towards the build up of
the modern atom.