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Alchemists laid the groundwork for many chemical processes, such as the refining of ores, the production of gunpowder, the manufacture of glass and ceramics, leather tanning, and the production of inks, dyes, and paints.
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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.”
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He founded the Academy, an academic program which many consider to be the first Western university. Plato wrote many philosophical texts—at least 25.
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inventing the scientific method of analysis, which can be applied to multiple fields of study.
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Dalton not only formulated a new atomic theory to explain chemical reactions, upon which much of modern chemistry and physics is based
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when Elements are arranged in increasing order of Atomic Mass, the properties of every eighth Element starting from any Element are a repetition of the properties of the starting Element.
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In 1910 Robert Millikan succeeded in precisely determining the magnitude of the electron's charge.
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discovered that the volume of a gas decreases with increasing pressure and vice versa—the famous Boyle's law.
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He is considered to be the most important contributor to the development of the periodic table. His version of the periodic table organized elements into rows according to their atomic mass and into columns based on chemical and physical properties
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German physicist Heinrich Rudolf Hertz. In connection with work on radio waves, Hertz observed that, when ultraviolet light shines on two metal electrodes with a voltage applied across them, the light changes the voltage at which sparking takes place.
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The radioactivity of uranium was discovered in 1896 by Henri Becquerel who, starting from a wrong idea, progressively realized what he was observing, regularly informing the French Academy of Sciences of the progress he was doing.
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the electrons were embedded in a uniform sphere of positive charge, like blueberries stuck into a muffin.
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Matter emits or absorbs energy in the small packets of energy called quantum and specifically in the case of light are called photons. The energy of a quantum is directly proportional to the frequency of the radiation.
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Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus.
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According to the Bohr model, often referred to as a planetary model, the electrons encircle the nucleus of the atom in specific allowable paths called orbits.
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he arranged the elements in the periodic table according to atomic numbers. He realized his findings indicated that the identity of an element is how many protons it has.
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The discovery of the proton is credited to Ernest Rutherford, who proved that the nucleus of the hydrogen atom (i.e. a proton) is present in the nuclei of all other atoms in the year 1917. Based on the conclusions drawn from the gold-foil experiment, Rutherford is also credited with the discovery of the atomic nucleus.
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helped them to detect where the electron could be at any given moment. The significance was that electrons had extremely unpredictable behaviors, but physicist Erwin Schrödinger's experiment tamed the situation
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we cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy;
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announced that the core also contained a new uncharged particle, which he called the neutron.