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John Dalton's Atomic Theory
John Dalton made the discovery that atoms are smooth round balls that could not be broken into smeller pieces. He also found that atoms are made up of elements. For example, gold atoms are made of gold elements. This was important because it showed what atoms looked like and what makes up certain materials. -
Dmitri Meendeleev
Dmitri Meendeleev made the first period table based on the chemical elements. This was important because it led to be one of the most important parts of chemistry and lead to the discovery of more elements. His version of the periodic table went by the atomic weight but now is arranged by the atomic number. (number of protons) -
JJ Thomson's Theory
Dalton discored that atoms have a negative charge. He used a vacuum tube with metal plates to create an eletric charge. He placed a magnet above the beam and it bent proving that there is a positive and negative charge. -
Earnest Rutherford's Model
Rutherford discovered that atoms were mostly empty space but had a nucleus in the center. He should atoms at a piece of gold foil, some passed through others reflected off. This discovery was important because it showed that atoms have a nuclues with a positive charge. -
Niels Bohr's Atomic Theory
Niels Bohr found that there are negatively charged electrons in the atom that orbit the nuclues like planets around the sun. There are three different rings the electrons can move in. Each ring has a different number of electrons in it. This theory is important because it showed that there were positive, negative, and neutral charges in an atom. -
James Chadwick's Atomic Discovery
James Chadwick discovered the Neutron. This discovery was very important because it showed that the atom had protons, neutrons, and electrons. The Neutrons have no charge and make up most of the mass.
