-
John Dalton
John Dalton was one of the first to develop an Atomic Model. He believed: 1)All matter is made of atoms. Atoms are indivisible and indestructible. 2) All atoms of a given element are identical in mass and properties 3) Compounds are formed by a combination of two or more different kinds of atoms. 4) A chemical reaction is a rearrangement of atoms. -
Dalton Model
The exsistence of protons and neutrons were unkown for him. -
William Crooke
William Crooke achieved a lot of things: Discoverer of the Selenocyanides; Thallium, a new element, 1861; Repulsion resulting from Radiation, 1873; the Radiometer, 1875; Illumination of Lines of Molecular Pressure, 1878; Radiant Matter, 1879, an ultra-gaseous, fourth state, of matter; Radiant Matter Spectroscopy, 1881; New Elements in Gadolinite, etc, 1886; Genesis of Elements, 1887; Some Possibilities of Electricity, Wireless Telegraphy, 1892; Fixation of Atmospheric Nitrogen, 1898; the Spintha -
JJ. Thomson
JJ. Thomson discovered in 1898, theorized that the negative electrons in an atom were like plums inside a 'pudding' of positive matter with the two charges neutralizing each other. This helped to improve the theory of the atomic structure and resulted in his being knighted in 1908 -
Ernest Rutherford
Ernest Rutherford discovered the atomic nucleus. Starting sometime around 1909, Rutherford began to notice that alpha particles would not always behave in accordance to the plum pudding model of an atom when fired at a piece of gold foil. These observations stimulated further research that was eventually published in 1911 and has been known ever since as Rutherford's Gold Foil Experiment. Which led to assumption and the confirmation atoms contained a nucleus. -
Niels Bohr
Niels Bohr discovered the atomic structure, and also proved that Rutherfords theory about the structure was incorrect. He proved that electrons cant be placed randomly they are quantified meaning that they orbit in a certain way. He compared it to the solar system. -
James Chadwick
In 1932, Chadwick made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons - elementary particles devoid of any electrical charge. Winning him the Nobel Prize in 1935 -
Thomson's Atomic Model
Thomson's atomic model was proposed in 1904 and was called the plum pudding model. He said that no matter where matter came from, it contained particles that were the same and are smaller than the atoms that matter is formed from. -
Rutherford Model
Rutherford's atomic model showed that most alpha particles went right through the gold foil but to his amazement a few alpha particles rebounded almost directly backwards. Which led to the conclusion the atom contained a nucleus. -
Bihr's Atomic Model
Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element. -
Modern Atomic Model
Electrons are in constant motion around the nucleus, protons and neutrons jiggle within the nucleus, and quarks jiggle within the protons and neutrons. This is the current model of the atom today. -
Sources:
http://www.rsc.org/chemsoc/timeline/pages/1803.html
http://www.chem.ox.ac.uk/icl/heyes/LanthAct/Biogs/Crookes.html
http://ffden-
https://sites.google.com/site/thomsonsexperiment/jj-thomson-s-atomic-model-and-theory
http://myweb.usf.edu/~mhight/goldfoil.html
http://www.iun.edu/~cpanhd/C101webnotes/modern-atomic-theory/rutherford-model.html
http://www.livescience.com/32016-niels-bohr-atomic-theory.html
http://www.nobelprize.org/nobel_prizes/physics/laureates/1935/chadwick-bio.html
