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384 BCE
Aristotle
Aristotle was born in Stagira, Chalcidice, Greece in 384 BCE. Aristotle helped contribute the fact that their is elements and that they are used in the atomic theory. Aristotle found this information by understanding the world around him and by being taught by plato. One interesting fact is that Aristotle thought that there was only five elements and not that there where many more. -
John Dalton
John Dalton was born in Manchester, England on September 6, 1766. He is mainly known for the discovery of the atomic theory the idea that only like atoms in a mixture of gases repel one another. Explaining why gases in a mixture behaved differently. No one really knows how he founded his results. A fun fact is that his theory is wrong. -
Billiard Ball Model
Dalton is the one who proposed the model. The main attributes to is model is that he thought atoms ( the smallest particles of matter) are solid like billiard balls hence the name. Research that supported this model is that atoms form together too form compounds so Dalton made wooden balls and joined them together to make model compounds so show physical proof. -
J.J. Thomson
J.J. Thomson was born in Cheetham Hill in Manchester on December 18, 1856. He contributed the discovery and identification of the electron and, the discovery of the first subatomic particle. His experiments where designed to study the nature of electric discharge by using a high-vacuum cathode-ray tube. A fun fact is that he became a physics by accident, he was actually intended to become an engineer. -
Max Planck
Max Planck was born in Kiel in Holstein, Germany on April 23, 1858. His contribution to the understanding of the atom is he is the initial founder of the quantum theory. Light and other electromagnetic waves are emitted in discrete packets of energy called quanta.He discovered this by studying black body radiation and coming up with and equation that explained the results of his tests.Fact, Max had four kids, three out of the four died. -
Marie Curie
Marie Curie was born in Warsaw, Poland on November 7, 1867. She is mainly known for her discovery of the element radium. She found this out by combining a certain amount of uranium and a certain amount of uranium atoms to get a certain intensity of radiation. Fun fact, Marie died due to exposure of radiation. -
Albert Einstein
Albert Einstein was born in Wurttemberg, Germany on March 14, 1879. He is best known for is theory of relativity and the equation E=MC2. Einstein made this discovery by looking at pollen grains in water and realizing that something smaller than pollen was making the pollen grains move around. One fun fact is that after Einstein died, his brain was removed so it could be studies by scientists. -
Niels Bohr
Niels Bohr was born in Copenhagen on October 7, 1885. He is mainly known for his work on the structure of atoms. Niels found his information by basing his work on Rutherfords discovery of the atomic nucleus and built it from there. He borrowed conceptions from the Quantium Theory and gradually was able to produce a picture. During world war two , Niels escaped to Sweden and America. -
James Chadwick
James Chadwick was born in Cheshire, England on October 20th, 1891. Chadwicks main discovery was the existence of neutrons. His discovery helped prove that neutrons are capable of penetrating and splitting the nuclei of even the heaviest elements. James Chadwick made his discovery by bombarding beryllium atoms with alpha particles causing an unknown radiation to appear. His discovery helped with the creation of the atom bomb. -
Plum Pudding Model
The Plum Pudding Model was proposed by J.J Thomson. He thought that atoms are composite objects,made of pieces with positive and negative charge, and that the negatively charged electrons within the atom were very small compared to the entire atom just like a plum pudding.What helped him come up with this model was at the time, atoms were known to be neutrally charged and Thomson knew that it had to have a source of positive and negative charge of electrons. -
Nuclear Model
Ernest Rutherford is the person who came up with this model. The model proposed that nucleus is positively charged and that the electrons orbit around the nucleus. Also, most of the atom is made up of empty space. A test that supported the model was to take foil and fire alpha particles at the foil sheet Ernest noticed that a few of the alpha bounced directly back with this information, Ernest came up with this model. -
Bohr Model
The Bohr Model was created by Niels Bohr. It proposed that the closer an electron is to the nucleus, the less energy it needs, but the farther away it is, the more energy it needs. Research that proves this model is real is when energy is released by electrons it occupies the portion of the electromagnetic spectrum that humans detect as visible light. And the slight variations in the amount of the energy can be seen as light of different colors. -
Citations
-“Joseph John ‘J. J." Thomson.” Science History Institute, 11 Jan. 2018, www.sciencehistory.org/historical-profile/joseph-john-j-j-thomson.
-Brainard, Jean. “Dalton's Atomic Theory.” CK-12 Foundation, CK-12 Foundation, 6 Sept. 2018, www.ck12.org/c/physical-science/daltons-atomic-theory/lesson/Daltons-Atomic-Theory-MS-PS/.
-Ross, Sydney. “John Dalton.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 23 July 2018, www.britannica.com/biography/John-Dalton/Atomic-theory. -
Citations
-“Atomic Structure: The Bohr Model.” Dummies, www.dummies.com/education/science/chemistry/atomic-structure-the-bohr-model/.
-“Nuclear Model.” Home, thehistoryoftheatomicmodel.weebly.com/nuclear-model.html.
-“Plum Pudding Model.” Annenberg Learner, www.learner.org/courses/physics/glossary/definition.html?invariant=plum_pudding.
-“The Nobel Prize in Physics 1935.” Nobelprize.org, www.nobelprize.org/prizes/physics/1935/chadwick/biographical/ -
Citations
-“The Nobel Prize in Physics 1922.” Nobelprize.org, www.nobelprize.org/prizes/physics/1922/bohr/biographical/.
-“Albert Einstein.” Biography.com, A&E Networks Television, 27 July 2018, www.biography.com/people/albert-einstein-9285408.
-“Marie Curie and The Science of Radioactivity.” The Carbon Dioxide Greenhouse Effect, history.aip.org/exhibits/curie/.
-“MAX PLANCK.” Edwin Hubble - Important Scientists - The Physics of the Universe, www.physicsoftheuniverse.com/scientists_planck.html.
