Quantum Mechanics free essay sample

Throughout the years the Quantum Mechanic model has evolved many times. This evolution has taken place after every major discovery in Quantum Mechanics. The current Quantum mechanic model is by far the most accurate example of an atom and how it works. Currently the model depicts a proton (or more than one depending on the atom) and neutron in the nucleus and a an electron rotating around the nucleus in an energy level, or an estimated path of the electron. The first person to purpose the existence of atoms was Democritus. Democritus’ had the right idea however the details of his original theory were not quite right. Democritus believed there was a select few elements and the ratio between these elements made up matter. It was free thinking individuals like this that led to the discovery of several theories that aloud atoms to be tested. Francois Bacon was one of those individuals. He saw a need for organization in the scientific community. His answer to this was the scientific method. The scientific method was a list of steps that helped organize experiments. Antoine Lavoisier was a French nobleman that had made a hobby of chemistry. However because of this bored tax collector with a passion we were able to accurately test countless theories. Lavoisier created the â€Å"Law of Conservation of Matter,† which stated that no matter could be created or destroyed. This Law caused a flurry of questions, were did this come from and where did that go became a question in every experiment. Robert Boyle now armed with new scientific knowledge began to concentrate on gases. Boyle declared in 1662 that, â€Å"For a fixed amount of gas kept at a fixed temperature, P and V are inversely proportional. † After Boyle many followed in the study of gases. Two scientists who chose to study this were Amedeo Avogadro and Joseph Louis Gay-Lussac. Amedeo Avogadro had hypothesized that Equal volumes of gases, at the same temperature and pressure, contain the same number of particles, or molecules (this was found true in 1811). Joseph Louis Gay-Lussac decided to compare and observe temperature in relation to pressure. Through his experiments he proposed, â€Å"At constant pressure, the volume of a given mass of an ideal gas increases or decreases by the same factor as its temperature (in kelvin) increases or decreases. These three laws allowed for an in depth observation of compounds and mixtures. Joseph Proust took notice of all the experiments conducted by his peers, and observed their conclusion which led him to the discovery of the law of definite proportions. This law states that all compounds contain the same ratio of elements. The law of definite proportions gave a perfect base for John Dalton to begin his atomic theory. Joseph Dalto n established a series of rules that elements and there atoms followed. Several of these rules were already accepted in the scientific community however Dalton was the first to list them. This list was known as the Atomic Theory, and it states: All atoms of a given element are identical Elements are made of tiny particles called atoms. The atoms of a given element are different from those of any other element. Atoms of one element can combine with atoms of other elements to form compounds. A given compound always has the same relative numbers of types of atoms. Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical process. A chemical reaction simply changes the way atoms are grouped together. The atomic theory though mostly true had an additional statement that proved to be false. This kept the atomic theory from being embraced for several years. Even though some of his ideas proved to be a little incorrect he paved the way for people such as J. J. Thomson, James Chadwick, and Ernest Rutherford to further investigate the atom. However before they had a chance to further investigate the atom a scientist by the name of Benjamin Franklin decided to do possibly the most famous scientific experiment of all time. The famous kite experiment is still debated however it did prove the existence of static electricity. Static electricity is the rapid expulsion of recently acquired negatively or positively charged ions. Ben Franklin’s kite experiment As scientists discovered more and more details about atoms they eventually wanted to break down the atom into its smallest particles. The first person to do this was J. J. Thomson. Thomson discovered the electron through his work with the cathode ray. A Cathode Ray was a device that used an evacuated glass tube with electrode at both ends, these electrodes had opposing charges. A beam of negatively charged particles flowed between the two electrodes. Thomson discovered this and called the negative particles electrons. Cathode Ray This breakthrough discovery of the electron caused uproar in atomic physics. Several scientists started experimenting and testing the electron. One of those scientists was Robert Andrews Millikan. Using an experiment involving oil-droplets Millikan found the charge of a single electron. However a scientist by the name of Felix Ehrenhaft published contradictory results. After improving his experiment Millikan’s original answer was proven correct . Ernest Rutherford was an intelligent son of a farmer. Because, of his work ethic and success in school he won a scholarship to Cambridge university. While studying in Cambridge he met J. J. Thomson who convinced him to start a career in observing and researching atoms. He discovered the nucleus and discovered it was the only part of the atom with mass and that it had a positive charge. In 1907 while experimenting with radioactivity Rutherford isolated a positive particle, he had discovered the proton. James Chadwick worked under Rutherford and was also studying radiation. However when observing the atomic mass of elements he noticed it was much higher than the elements atomic number. Sense the electron has no mass he hypothesized that there was a neutrally charged particle that contained mass. He was correct and named the particle a neutron. After each part of the atom was identified the problem of the atoms structure was called into the equation. Neils Bohr decided to focus his time on this problem. Rutherford had already illustrated an atomic model however it had a serious problem. His structure had the electron rotating around the nucleus however if this were true the electron would lose energy and eventually collide into the nucleus. Bohr decided by adding energy levels for the electrons to transfer to it fixes the basic physics problems. During the discussions of the atomic model the word quantum mechanics started being used. Quantum Mechanics means the study of radiation and matter. The main founders of quantum mechanics are Werner Heisenberg, Niels Bohr, and Wolfgang Pauli. Werner Heisenberg was head of the German Nuclear power program and was incredibly close to a nuclear bomb if it weren’t for a math error in 1940 causing him to believe nuclear fission was impossible. Wolfgang Pauli had a break through with his Pauli exclusion principle. This principle discussed how matter occupies space exclusively. All these scientific evolutions have given us some answers as to how we function on an atomic level. However some will say we haven’t even scratch the surface due to the fact the smallest particle we’ve identified is the quark. The discovers that we will make in the future after identifying even smaller particles will more than likely prove our current thoughts wrong. This thought process is in danger of being proved wrong. Scientist are working on something called the string theory that will explain time and other unknowns. In conclusion the current quantum mechanic model has few inaccuracies and the general physics are correct. The electron cloud isn’t illustrated by red ovals like it used to be and the separate energy levels are visible. 00 years of testing and experiments have gone into the model and that makes it very accurate.