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The alchemists created the first 4 elements, aswell as common tools such as flasks and funnels -
Plato proposed that matter was continuous, infinite, and present in every form. He also taught royal families. -
Democritus believed that atoms were uniform, hard, solid, indestructible and incompressible. Atoms moved in infinite numbers through empty space until stopped. He set the basic of atoms for the world. He was considered the father of science -
Robert Boyle made the law that states; If the volume of a gas decreases, the pressure increases proportionally. He also came up with the idea that elements are made up of corpuscles or atoms which come in various shapes and sizes. -
Antoine Lavoisier found out that the total mass of products of a chemical reaction is the same as the total mass of the starting materials consumed in the reaction. He put this to the test and discovered one of the most basic principles of chemistry: the law of conservation of matter, which states that matter is preserved in chemical reactions. -
John Dalton created the theory which states; All matter is composed of tiny, definite particles called atoms. Atoms are indivisible and indestructible -
Dalton's Billiard Ball Model Dalton believed that atoms were the tiniest units of matter, and he saw them as solid, hard spheres, similar to billiard balls, therefore he modeled them with wooden balls. -
Amedeo Avogadro stated that the volume of gases at room temperature contain the same number of molecules. This helped organize the Periodic Table. -
Dmitri Mendeleev developed the periodic classification of the elements. When all know elements were ordered by increasing atomic weight, the table displayed an occurring pattern of groups groups within the elements. -
Like negatively charged "plums" contained in a positively charged "pudding," electrons are surrounded by a volume of positive charge in the plum pudding concept. -
JJ Thompson made the discovery that atoms were made up of small components. He also made the plum pudding model. -
Einstein made the theory which states any liquid is made up of molecules and these molecules are random ceaseless motion. -
Robert Millikan discovered that there is an electric charge in an electron. His experiments showed that atoms had a small dense positively charged nucleus. -
Ernest Rutherford discovered the atomic nucleus. This is the small dense region containing protons and neutrons -
This couple discovered polonium and radium (1898), radioactivity (1903) and managed to isolate pure radium(1911) -
The "solar system" model shows an atom as a massive positive entity (the nucleus/sun) with negative entities (electrons/planets) circling around it. This model was made by Ernest Rutherford. -
Neils Bohr proposed a theory based on a quantum theory about the hydrogen atom. This states that electrons moved around the nucleus but only in prescribed orbits. -
Henry G. J. Mosely created the concept of the atomic number on the Periodic Table. He also created the law which is a systematic relation between wavelength and atomic number -
Erwin Shrödinger established the wave mechanics formula which portrayed the electrons as waves, spread out in any given location. He also created the Electron Cloud Model. -
A model of an atom in which the nucleus is small but massive and is surrounded by a cloud of swiftly moving electrons is known as an electron cloud model. This model was made by Erwin Shrödinger. -
Werner Heisenberg discovered the Uncertainty Principle which states that a particle's position and moment can't be know exactly. -
James Chadwich discovered the neutron (1932). In 1941, he wrote the final draft of the maud report which inspired the United States government to begin serious atomic bomb research efforts.