-
100
The Alchemists
• They tried to see if they could use previous theories to make new things from metal, such as gold. Even though they failed at this, they did give us more information that we classify as chemical properties.
• They studied many different processes like calcination, distillation, fermentation, and sublimation. -
460
Democritus
• He formed, what we think was, the first atomic theory, by claiming that that everything is made up of Earth, Water, Fire and Air. Some consider him to be the father of modern science.
• Claimed that everything was made up of atoms, which are physically indivisible. He said that there are infinite numbers of atoms and kind of atoms out there with all kinds of different sizes and shapes. -
John Dalton
• He based his theory on the premise that atoms of different elements can be acclaimed by the difference in their weights.
• His theory states numbers of basic ideas about the atom theories. -
JJ Thompson
• Once he discovered the electrons, he came up with a new theory that atoms are made up of smaller particles. He proved his theory by using the Cathode Ray Tube.
• In the Cathode Rays he showed that there are negative and positive particles in the atoms and that they are a part of the atom. -
Neils Bohr
• He was interested in physics at a young age, and studied the subject throughout his graduating years. He earned the doctorate in physics.
• He is one of the top scientists of modern physics, best known for the sustantial contribution to the quantum theory and his Prize-winning research on the structure of atoms. -
Earnest Rutherford
• He is responsible for the discovery of alpha and beta rays, set forth the laws of radioactive decay, and identified alpha particles as helium nuclei.
• But most importantly he assumed the nuclear structure of the atom. Experiments done by his theory show that when alpha particles are fired into gas atoms, a few of them deflect which indicate a dense positively charged region contenting most of the atomic mass.
