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Hennig Brand tried to create an object that could turn metals into gold.
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Robert Boyle also discovered phosphorus, and it became public.
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Johann Dobereiner grouped similar elements, this was the start of teh periodic table.
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at lease 47 elements were discovered, and scientists started to see patterns in the characteristics
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Middle element in the triad had atomic weight that was the average of the other two members- this was the law of the triads
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In 1863 English chemist John Newlands divided the than discovered 56 elements into 11 groups, based on characteristics.
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he wrote a paper proposing the Law of Octaves which was elements exhibit similar behavior to the eighth element following it in the table.
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dimitri mendeleev arranged chemical elements by atomic mass. he also predicted the discovery of other elements, and left spaces open in his periodic table for them.
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dimitri then arranged elements by atomic weights and properties. Mendeleev's periodic table of 1869 contained 17 columns with two periods of seven elements each followed by two nearly complete periods.
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Antoine Bequerel first discovered radioactivity. three types of radiation; alpha, beta and gamma rays.
Marie and Pierre Curie started working on the radiation of uranium and thorium, which lead to the discoverey of radium and polonium. They discovered that beta particles were negatively charged. -
He performed x-rays on know elements. he was able to see relationships between them
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In 1894 Sir William Ramsay and Lord Rayleigh discovered the noble gases, which were added to the periodic table as group 0.
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J. J. Thomson first discovered electrons. John Townsend and Robert Millikan determined their exact charge and mass.
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Bequerel discovered that electrons and beta particles which were identified by the Curies are the same thing.
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Rutherford announced that radioactivity is caused by the breakdown of atoms.
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In 1906, Mendeleev came within one vote of receiving the Nobel Prize in chemistry.
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Rutherford and German physicist Hans Geiger discovered that electrons orbit the nucleus of an atom.
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Bohr discovered that electrons move around a nucleus in energy called orbitals. Radiation is emitted during movement from one orbital to another.
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Rutherford first identified protons in the atomic nucleus. English physicist Henry Moseley provided atomic numbers, based on the number of electrons in an atom, rather than based on atomic mass.
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Glenn Seaborg identified lanthanides and actinides, which are usually placed below the periodic table.
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James Chadwick first discovered neutrons, and isotopes were identified.
In that same year Cockroft and the Walton first split an atom by bombarding lithium in a particle accelerator, changing it to two helium nuclei. -
By 1860 about 60 elements were known.