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Democritus was a central figure in the development of the atomic theory of the universe. He theorized that all material bodies are made up of indivisibly small “atoms. -
It is a notion commonly acknowledged that in his work Plato laid down an early chemical theory of the creation, of the universe -
A solar system is a group of planets and other bodies that revolve around a star. -
Robert Boyle discovered that the volume of a gas decreases with increasing pressure and vice versa -
Alchemists made all sorts of materials for commerce, including medicines, pigments, metallic alloys, perfumes and cosmetics -
The first breakthrough in the study of chemical reactions resulted from the work of the French chemist Antoine -
He defined an atom to be a ball-like structure, as the concepts of atomic nucleus and electrons were unknown at the time. -
John Dalton was an English chemist, physicist. He introduced the Atomic theory into chemistry. -
He was the first to make a distinction between molecules of a substance and its atoms -
Building the Periodic Table of the Elements. Dmitri Mendeleev, a Russian chemist and teacher, devised the periodic table -
In 1897 Thomson discovered the electron and then went on to propose a model for the structure of the atom. -
He and Marie discovered radium and polonium in their investigation of radioactivity. -
the electrons were embedded in a uniform sphere of positive charge, like blueberries stuck into a muffin. -
Einstein also in 1905 mathematically proved the existence of atoms, -
postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay. . -
In 1909 Millikan began a series of experiments to determine the electric charge carried by a single electron. He began by measuring the course of charged water droplets in an electric field. -
Known as Moseley's law, this fundamental discovery concerning atomic numbers was a milestone in advancing the knowledge of the atom. -
Niels Bohr proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. -
An electron is a negatively charged subatomic particle.The other two are protons and neutrons. -
He discovered a neutron is a particle with no electric charge that, along with positively charged protons, makes up an atom's nucleus.