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Dalton Atomic Theory
He formulated the first modern description of chemical structures. His theory was that elements are made up of specific atoms in a certain ratio to make a compound. This is important because that's how we think of compounds today. Example H2O. -
Mendeleev
Mendeleev created the periodic table of elements. He listed them in order by atomic number. There were 60 elements in the periodic table. This is important because it is still used today and it is in order of least to greatest by the atomic number wihch is the number of protons. -
Thomson Atomic Model
He discovered the electron through expiriments using a cathode ray tube. Magnets can bend the cathode ray of electrons in a cathode ray tube. He came up with the Plum Pudding theory which is that there are positive and negative charges inside an atom. It is important because his theory helps us understand electrons. -
Rutherford's Planetary Modelof the Atom
Rutherford discovered the nucleus. He shot alpha particles through gold foil and some went through and some bounced back. He found that the nucleus had a positive charge because the particles came shooting back. He said that the positive charge was in the middle and that there were negative charges around the positive nucleus. His discoveries contributed to the fields of radioactivity and nuclear physics. -
Bohr Atomic Model
Bohrs theory is similar to Rutherford in that electrons which are negative charges, surround the nucleus which is a positive charge, but the electrons go around in specific orbits. It is important because it helps the understanding of the struture of atoms. -
Schrodiner Atomic Model
Shrodinger said that electrons are more like waves than particles. Important because he introduced the concept of quantom in explaining atomic properties. -
Democritus Atomic Model
(490 BCE) Democritus expanded the atomic theory of Leucippus. Matter is made up of atoms seperated by empty space. There are different shapes and sizes of atoms and atoms are so small that they are undivisible. It is important because the theory is the beginning of the history of the Atomic model.
