Throughout the discovery of the atom, many scientists worked to formulate howthe atom works. Which began in the early 1800’s with John Dalton, to ourcurrent model of the electron cloud developed by Schrodinger. During this longprocess of the discovery the atom, took many models and scientists. The entiregroup of scientists who assisted in the discovery of the atom used eachother’s model to improve each other’s theories. Firstly, John Dalton showedthat, collectively, the three laws, the law of definite proportion, the law ofconversation of masses, and the law of multiple proportion.
These three lawsdemonstrate the existence of the atom. Also, Using these three laws he developeda theory called, Dalton’s Atomic Theory. This includes five basic principles;1) all matter is made of indivisible and indestructible atoms, 2) atoms of agiven element are identical in their physical and chemical properties, 3) atomsof different elements have different physical and chemical properties, 4) atomsof different elements combine in simple whole-number ratios to form chemicalcompounds, 5) atoms cannot be subdivided, created or destroyed when they arecombined, separated, or rearranged in chemical reactions. However, afterscientists look more carefully at his points they found some weaknesses.
Oneweakness was that the atom was found to be indivisible, and they had smallerparticles. After Dalton came up with the five points, J. J. Thompson came along. He discovered that charged and magnets deflected the straight paths of cathoderays. In addition, he discovered negative and positive charged particles.
Hestated that the atom was made of smaller particles called, electrons andprotons. In the discovery of the electron he used the Cathode-ray tube. As heresearched he came up with a model of the atom, he stated that the atom was a”plum pudding model. ” This model featured negatively charged electronsembedded in a ball of positive charge. After, J.
J. Thompson came ErnstRutherford, who was a student of Mr. Thompson. He created “gold-foilexperiment” which untimely-disproved J. J.
Thompson’s theory. In thisexperiment 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 offthe 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 thiswas that the particles that bounced off the nucleus and the particles that wentstraight through traveled in the empty space.
The major was that his experimentwas 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 tofurther our knowledge of the atom. In his model, he purposes that the electronsin the atom can reside only to certain energy levels. He related his model to aladder, a person can stand on the rungs of the ladder, and however it isimpossible for a person to stand between the rungs.
The only way for theelectron to jump to the next level is for it to have a Quantum leap. Which isthe leap from one energy level to another, and the lowest energy level is calledthe ground state. Thus, comes to the conclusion that electrons are quantized. Helping Bohr’s model become superior, Plank declared that energy comes inpackets or bundles of energy that is discontinued. This went all againstclassical science and he was not favored with the other scientist. Helping proveBohr’s model he used the bright-line spectrum, which helped him prove hismodel.
There was one flaw in his model, which was that it did not work withmultiple elements. After Bohr and Plank, another educated scientist came alongwho was DeBroglie, he purposed the Wave Particle Duality Theory. This theorystated that matter can act like waves, and waves can act like particles. Toprove his theory he used the mathematical expression of mc=hc.
Which meant thatthe m stood for the mass particles and the stood for the wavelength. TakingDeBroglie’s model to a further extent was Heisanburg; he treated electrons asparticles. He came up with the uncertainly principal. In addition, he statedthat the exact location of the electron couldn’t be determined. However, hecould predict a region in space where the probability of finding the electron ishigh. This predicted region of high probability was named the electron cloud.
The electron cloud was like a chaotic motion of electrons. However, Heisanburgdid not treat the electron as a wave. On the other hand, Schrodinger consideredthe electron as a wave. Furthermore, he modified the wave equation, to formclassical physics to fit the concept. In the equation, Schrodinger relates theprobability region directly to the energy region. In the result of this action aplot 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 differentmodels and ideas. Furthermore, each one of the scientists used one another toprogress the model of the atom. With each one of the scientists contributing tothe model, we were able to create a good model. By using the scientific methodwe gain the information of the atom, and we will continue to learn about it asmore scientists come along.
