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In 500 B.C. The Alchemists discovered the 4 basic elements known as fire, wind, water, and Earth. These elements led the periodic table to be made. -
In 427 B.C.E. Plato discovered that there's 5 solid shapes. Which atoms must come from one of the 5 shapes. -
In 400 B.C.E. Democritus had a theory that atoms are the basic building block of matter. He's stating that all matter is made from atoms. -
in 1662 Robert Boyle discovered that as the volume of a gas decreases, the pressure increases. This discovery is known as the Boyle's Law. -
Antone Lavoisier in 1789 had the theory that in combustion, oxygen is necessary. This means for something to burn, oxygen must be invovlved. -
John Dalton had discovered that all matter is made up of atoms. In his discovery he specified that the atoms are invisible and indestructible. -
This model was made with wooden circular balls. This was useful because it represented the solid and sphere shaped particles. -
in 1811 Avogadro discovered that when there's the same volume of pressure, temperature, and gas. Then there'll be the same number of molecules. -
Dmitri is the man who made up the symbols for chemical elements based on their atomic weight. These symbols are used for the periodic table. -
JJ Thompson discovered that atoms are composed of electrons. For every atom there will be electrons found. -
The Plum Pudding Model showed how electrons are in a shape of positively charged electrons. They're clumped together, being embedded with one another. -
In 1905 Albert Einstein was the first person to prove matematically that atoms exist. He did so by calculating the force of a grain of pollen floating on water. -
Robert Millikan had the discovery that there's a fundamental charge. This charge is known as the charge of electrons. -
Ernest Rutherford, didn't necessary have a discovery. He was the first person to ever cut the nucleus into half. -
Neils Bohr had the discovery that in the orbit of the nucleus, an electron can only occupy a few orbits. This means the electron can only go to certain orbits and not multiple at once. -
This model was a plantary model which was meant to replicate the solar system. It showed that electrons are in a circular orbit around the nucleus. -
Mosely's theory was that the atomic number is the amount of positive charges. The charges are in the nucleus. -
Werner contributed by the discovery that the momentum and position of a particle both won't be identified. Only one will be known. -
James in 1932 proved that neutrons exist. To add on, he proved that particles weaken any electrical charge -
The Electron Cloud Model included a dense nucleus. Which was covered by different levels in orbit. -
In 1962 Erwin made an equation for when electrons in an atom are distributed. He discovered that they are distributed in a circular motion. -
The two of them discovered in 1989 that in uranium there's polonium and radium. These two elements are radioactive.