Chemistry And Atom
Throughout the discovery of the atom, many
scientists worked to formulate how
the atom works. Which began in the early
1800’s with John Dalton, to our
current model of the electron cloud developed
by Schrodinger. During this long
process of the discovery the atom, took many
models and scientists. The entire
group of scientists who assisted in the
discovery of the atom used each
other’s model to improve each other’s
theories. Firstly, John Dalton showed
that, collectively, the three laws, the
law of definite proportion, the law of
conversation of masses, and the law of
multiple proportion. These three laws
demonstrate the existence of the atom.
Also, Using these three laws he developed
a theory called, Dalton’s Atomic
Theory. This includes five basic principles;
1) all matter is made of
indivisible and indestructible atoms, 2) atoms of a
given element are
identical in their physical and chemical properties, 3) atoms
of different
elements have different physical and chemical properties, 4) atoms
of
different elements combine in simple whole-number ratios to form
chemical
compounds, 5) atoms cannot be subdivided, created or destroyed when
they are
combined, separated, or rearranged in chemical reactions. However,
after
scientists look more carefully at his points they found some
weaknesses. One
weakness was that the atom was found to be indivisible, and
they had smaller
particles. After Dalton came up with the five points, J.J.
Thompson came along.
He discovered that charged and magnets deflected the
straight paths of cathode
rays. In addition, he discovered negative and
positive charged particles. He
stated that the atom was made of smaller
particles called, electrons and
protons. In the discovery of the electron he
used the Cathode-ray tube. As he
researched he came up with a model of the
atom, he stated that the atom was a"plum pudding model." This model featured
negatively charged electrons
embedded in a ball of positive charge. After,
J.J. Thompson came Ernst
Rutherford, who was a student of Mr. Thompson.
He created "gold-foil
experiment" which untimely-disproved J.J. Thompson’s
theory. In this
experiment he directed a beam of alpha particles at a very
thin gold foil sheet.
This was so the Rutherford could measure the angles
of the particles coming off
the gold foil. Sheet. Most of the alpha particles
went through the sheet,
however some of the particles hit the foil and
bounced back. The reason of this
was that the particles that bounced off the
nucleus and the particles that went
straight through traveled in the empty
space. The major was that his experiment
was that the atom would eventually
lose its energy and collapse in the nucleus.
Around 1913, a Danish
physicist named Niels Bohr came up with a new model to
further our knowledge
of the atom. In his model, he purposes that the electrons
in the atom can
reside only to certain energy levels. He related his model to a
ladder, a
person can stand on the rungs of the ladder, and however it is
impossible for
a person to stand between the rungs. The only way for the
electron to jump to
the next level is for it to have a Quantum leap. Which is
the leap from one
energy level to another, and the lowest energy level is called
the ground
state. Thus, comes to the conclusion that electrons are
quantized.
Helping Bohr’s model become superior, Plank declared that
energy comes in
packets or bundles of energy that is discontinued. This went
all against
classical science and he was not favored with the other
scientist. Helping prove
Bohr’s model he used the bright-line spectrum,
which helped him prove his
model. There was one flaw in his model, which was
that it did not work with
multiple elements. After Bohr and Plank, another
educated scientist came along
who was DeBroglie, he purposed the Wave
Particle Duality Theory. This theory
stated that matter can act like waves,
and waves can act like particles. To
prove his theory he used the
mathematical expression of mc=hc. Which meant that
the m stood for the mass
particles and the stood for the wavelength. Taking
DeBroglie’s model to a
further extent was Heisanburg; he treated electrons as
particles. He came up
with the uncertainly principal. In addition, he stated
that the exact
location of the electron couldn’t be determined. However, he
could predict a
region in space where the probability of finding the electron is
high. This
predicted region of high probability was named the electron cloud.
The
electron cloud was like a chaotic motion of electrons. However,
Heisanburg
did not treat the electron as a wave. On the other hand,
Schrodinger considered
the electron as a wave. Furthermore, he modified the
wave equation, to form
classical physics to fit the concept. In the equation,
Schrodinger relates the
probability region directly to the energy region. In
the result of this action a
plot of equations provides a three dimensional
picture of the electron cloud.
Schrodinger’s theory of the atom is our
current model of the electron cloud.
Throughout, the existence of the
atom many scientists came up with different
models and ideas. Furthermore,
each one of the scientists used one another to
progress the model of the
atom. With each one of the scientists contributing to
the model, we were able
to create a good model. By using the scientific method
we gain the
information of the atom, and we will continue to learn about it as
more
scientists come along.