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Democritus claims everything is made up of smallest particles and named then atoms. -
Plato claims that everything is made up of tiny geometrical shapes containing the elements of air, water, earth, and fire. -
Aristotle states everything is made of either water, air, earth, or fire and that a void between atoms could exist. -
Alchemists believed that they could make base metal turn into gold using similar substances using the right ratios paving the way for common chemistry. -
Boyle finds that everything is made of tiny particles and calls them corpuscles. Now known as the atom. -
Dalton makes the Atomic Theory stating that everything is made up of invisible and indestructible small things called atoms. -
Newland claimed that when the elements are arranged in atomic mass order, there will be similarities between the first interval and eighth interval. -
Mendeleev creates the common periodic table. -
Hertz experiments with charged particles on metal plates to find that particles may be electrically charged. -
Millikan discovers the charge of a single electron. -
Becquerel discovers radioactivity when experimenting how uranium salts are affected by light. -
Planck states that light is emitted as a continuous wave in packets of energy called photons. -
Thomson experiments show that all atoms have subatomic particles called electrons with negative charges. -
Rutherford finds out that atoms are mostly empty space with a positively charged nucleus. -
Bohr discovered a model that shows where and how the electrons orbit the nucleus in their circular paths. -
Mosley gave elements all their number that represents their order and the number of positive protons. -
Rutherford discovered the proton when he experimented with nitrogen atoms and alpha particles. -
Schrodinger creates a linear equation that shows a wave function of non-realistic quantum-mechanical system. -
Heisenberg finds that we cannot find the exact speed or position of the photons or electrons. Whenever you get closer to one's answer, you get further from the other answer. -
Chadwick uses beryllium and alpha particles to find there is a neutral particle in the atom similar to the proton.