Quantum Theory


     Quantum Mechanics is abranch of mathematical physics that deals with the
emission and absorption of energy by matter and with the motion of material
particles. Because it holds that energy and matter exist in tiny, discrete
amounts, quantum mechanics is particularly applicable to Elamentry Pprticlesand
the interactions between them. According to the older theories of classical
physics, energy is treated solely as a continuous phenomenon and matter is
assumed to occupy a very specific region of space and to move in a continuous
manner. According to the quantum theory, energy is emitted and absorbed in a
small packet, called a quantum (pl. quanta), which in some situations behaves as
particles of matter do; particles exhibit certain wavelike properties when in
motion and are no longer viewed as localized in a given region but as spread out
to some degree. The quantum theory thus proposes a dual nature for both waves
and particles, with one aspect predominating in some situations and the other
predominating in other situations. Quantum mechanics is needed to explain many
properties of matter, such as the temperature dependence of the specific heat of
solids, as well as when very small quantities of matter or energy are involved,
as in the interaction of elementary particles and fields, but the theory of

Relativity assumes importance in the special situation where very large speeds
are involved. Together they form the theoretical basis of modern physics. (The
results of classical physics approximate those of quantum mechanics for large
scale events and those of relativity when ordinary speeds are involved.) Quantum
theory was developed principally over a period of thirty years. The first
contribution was the explanation of blackbody radiation in 1900 by Max Planck,
who proposed that the energies of any harmonic oscillator, such as the atoms of
a blackbody radiator, are restricted to certain values, each of which is an
integral (whole number) multiple of a basic minimum value. Over the years there
has been a number of models that were supposed to have been atomicly correct.

Right now we are currently useing the Schrodinger model to show the atomic
structure of an atom. There also was other models of the atomic structure of an
atom but they were wrong. They were wrong because at those times there was not
enough tecknoladgy around to ptove other wise. The names of the major noted
scientists that had made a model of the atomic structure of an atom, are Bohr,

Rutherford, Thompsom, and Schrodinger. The current atomic theory is that

Schrodinger and the other scientists abandoned the idea of precise orbits, and
replaced it with a discription regions called orbitals. We have been useing that
same theory for almost eighty years now and it looks like we are not going to
change it still. Shrodinger's modelwas basically a cloud of sub atomic particles
in orbit around a nucleus. The electrons moved in orbit around the nucleus but
also moved in tiny orbitals. These orbitals are revolutions around possibly
another subatomic particle while in orbit around the nucleus which is holding
protons, neutrons, and other sub atomic particles. Another scientist that
created a model of the atomic structure of an atom was Rutherford. His model was
an model in which the the atom was held together by an electrical attraction
between the nucleus and the electrons. by electrical attraction between the
nucleus and the electrons. In this model the electrons travelled in relatively
distant orbits around the nucleus. The model eventually proved successful in of
chemistry and everyday physics. Subsequent studies of the atom divided into
investigations of the electronic parts of the atom, which came to be known as
atomic physics, and investigations of the nucleus itself, which came to be known
as nuclear physics. His experiment: He studied hydrogen by hitting it with
electricity. The electricity would excite an electron anc cause it to jump to
higher energy levels. When it fell back down, a photon was given off. The photon
of light corresponded with the amount of energy per energy level. Other
scientist also made models that had an impact on the scientific community. One
of them is Rutherford. In 1898, Rutherford obtained the physics professorship at

McGill University, Montreal. Rutherford proposed an atomic model in which the
atom was held together by electrical attraction between the nucleus and the
electrons. In this model the electrons travelled in relatively distant orbits
around the nucleus. The model eventually proved successful in explaining most of
the phenomena of chemistry and everyday physics. Subsequent studies of the atom
divided into investigations of the electronic parts of the atom, which came to
be known as atomic physics, and investigations of the nucleus itself, which came
to be known as nuclear physics. His experiment: His experiment was that he
bumbarded a sheet of gold foil with alpha particles, and discovered that the
atom was not a solid mass, but infact is made soly of empty space. Another
scientist that made a break through in the current model of the atomic structure
of an atom was known as Thompson. In 1895, Thomson discovered the electron. His
evidence came from the experiment he did using an apparatus that allowed him to
see the glow of the stream of negatively charged particals released when a gas
is subjected to intense electrical forces. These particals are known now to be
electrons. It was his experiments that proved that the atom was not an
indivisible particle. Instead, it was made up of different particles itself. In

1906, Thomson recieved a nobel prize for his discovories. Thomson's model of an
atom was a solid sphere with electrons embedded in the positive part of the
atom. The positive part of the atom makes up the bulk of the atom's mass and
volume. It was hypothesized that the positive part of the atom was fluid. John

Dalton was a english scientist. He taught mathematics and physical sciences at

New College, Manchester. Dalton revived the atomic theory of matter which he
applied to a table of atomic weights and used in developing his law of partial
pressures. He was color-blind and studied that affliction, also known as
Daltonism.