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Discovered solid forms of matter are composed of indivisible elements shaped like triangles. -
Discovered that atoms were uniform, solid, hard, incompressible, and indestructible and moved in infinite numbers through space until stopped. -
The Alchemists believed that all metals were formed from 2 principles, mercury and sulfur -
Discovered that everything was composed of very tiny particles. -
Discovered that matter was composed of atoms that were not created or destroyed during chemical reactions. -
Defined an atom to be a ball-like structure as the concepts of the atomic nucleus and electrons were unknown at the time. -
Discovered that all matter is made up of atoms and all atoms of a given element are identical in mass and properties. Also discovered that compounds are 2 or more different types of atoms. -
Equal volumes of gases at the same temperature an pressure contain the same number of molecules regardless of their chemical nature. -
Discovered that elements arranged according to the value of their atomic weights present a clear periodicity of properties. -
All atoms contain tiny negatively charged subatomic particles called electrons. -
Describes atoms as consisting of a nucleus with a number of electrons in orbits around the nucleus. -
Discovered that the powerful rays, or energy the polonium and radium gave off were actually particles from tiny atoms that were disintegrating inside the elements. -
Describes an atom as a negatively-charged electrons embedded within a positively charged soup. -
Mathematically proved the existence of atoms and that any liquid is made up of molecules. Also proved that these molecules are always in a random, ceaseless motion. -
Proved that electrons have a fixed measurable charge that does not vary and calculate the mass of a single electron -
Described the atom as having a tiny, dense, and positively charged core called the nucleus. -
Discovered that the square root of the frequency of the X-Ray emitted by an atom is proportional to it's atomic number -
Proposed a theory for the hydrogen atom that all electrons move around the nucleus -
Formulated a type of quantum mechanics based on matrices. -
Discovered that the behavior of electrons within atoms could be explained by treating them mathematically as matter waves. -
Shows a particular area in which an electron is likely to be -
Discovered that the atoms were not only made up of protons and electrons, but there were also neutrons.