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The Alchemists theorized that matter could be eternal. And that materials are made from particles. -
Theorized that atoms were specific to the material which they composed. -
Theorized that these solid forms of matter are composed of indivisible elements, shapes like triangles. -
Created by Nicolaus Copernicus, proposed a model of our Solar System -
Created Boyle's Law that demonstrates matter is made of tiny particles known as atoms today. -
Defined the Law of Conservation of Mass. Proves matter was composed of atoms, that were not created or destroyed during chemical reactions. -
Developed Dalton's Theory that suggested all matter was comprised of indivisible and indestructible atoms with masses and properties. -
Created by John Dalton, displays a model of an atom depicted in a ball-like structure. -
Developed two hypotheses. 1. That equal volumes of gas contain equal numbers of molecules. 2. Elementary gases such as Hydrogen, Nitrogen and Oxygen were composed of two atoms. -
Mendeleev discovered Periodic Law, and arranged the elements in order of increasing atomic mass. -
Experimented with cathode ray tubes, showed that all atoms contain tiny negatively charged subatomic particles. -
Discovered the strongly radioactive elements, Polonium and Radium. -
Created by JJ Thomson, depicted electrons embedded in a uniform sphere of positive charge. Like blueberries stuck in a muffin. -
Mathematically proved the existence of atoms. -
Demonstrated the atomic structure of electricity by using the "falling-drop method." -
Established that the mass of the atom is concentrated in its nucleus. -
Proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values. -
Collected the x-ray spectra of a variety of elements and found that the frequency of x-ray radiation has a precise mathematical relationship to an elements atomic number, -
Schrödinger formulated a wave equation that accurately calculated the energy levels of electrons in atoms. -
Created by JJ Thomson displays a dense nucleus surrounded by a cloud of electrons at various levels in orbitals. -
Chadwick discovered the Neutron in the atom.