Chemistry And Atom

     Throughout the discovery of the atom, many scientists worked to formulate how
the atom works. Which began in the early 1800ís 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
otherís model to improve each otherís 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, Daltonís 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. Thompsonís 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 Bohrís 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

Bohrís 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

DeBroglieís 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 couldnít 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.

Schrodingerís 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.