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The Alchemists believed all metals were formed from mercury and sulfur, the mercury gave the metal malleability, and the sulfur gave it body and calcination. -
Plato believed solid forms of matter are composed of indivisible elements shaped like triangles. -
Democritus believed atoms were uniform, solid, incompressible, and indestructible, and they moved in infinite numbers through empty space until stopped. -
Robert Boyle believed everything was composed of very tiny particles. -
Antoine Lavoisier believed that matter was composed of atoms that were not created or destroyed during chemical reactions. -
John Dalton believed elements consisted of invisible small particles, all atoms of the same element are identical, and atoms can neither be created or destroyed. -
John Dalton envisioned atoms as solid, hard, spheres, like billiard balls and used wooden balls to model them. -
Amedeo Avogadro believed equal volumes of gases at the same temperature and pressure contain equal numbers of molecules regardless of their chemical nature and physical properties. -
Dmitri Mendeleev believed elements arranged according to the value of their atomic weights present a clear periodicity of properties. -
Pierre and Marie Curie suggested that the powerful rays, or energy, the polonium and radium gave off were actually particles from tiny atoms that were disintegrating inside the elements. -
The plum pudding model shows the electrons were embedded in a uniform sphere of positive charge, like blueberries stuck into a muffin. -
Albert Einstein believed any liquid is made up of molecules, that are always in random, ceaseless motion. -
Robert Millikan believed electrons did have a discrete quantifiable charge -
Ernest Rutherford believed atoms have a tiny, dense, and positively charged core called the nucleus -
Niels Bohr believed that electrons moved around a nucleus, but only in prescribe orbits, and if electrons jump to a lower-energy orbit, the difference is sent out as radiation. -
Henry Moseley believed atomic numbers are the fundamental feature that describes an element. -
The solar system model describes atoms as consisting of a nucleus with a number of electrons in orbit around the nucleus. -
The electron cloud model represents the area around and atom's nucleus where electrons are most likely to be found. -
James Chadwick discovered the Neutron, which is a subatomic particle with no electrical charge. -
JJ Thomson believed all atoms contain tiny negatively charged subatomic particle or elements