CASED BASED SCI by ethanramos https://padlet.com/21900095/nr496qy2y0uty1vs Evolution Of Periodic Table en-us 2022-04-17 16:12:46 UTC 2025-10-25 12:18:56 UTC hello@padlet.com https://padlet.net/icons/png/1f468-1f52c.png 1669 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146089524 In 1669 German merchant and amateur alchemist Hennig Brand attempted to created a Philosopher’s Stone; an object that supposedly could turn metals into pure gold. He heated residues from boiled urine, and a liquid dropped out and burst into flames. This was the first discovery of phosphorus.






]]> 2022-04-17 16:30:49 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146089524 1680 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146090176 In 1680 Robert Boyle also discovered phosphorus, and it became public.



]]> 2022-04-17 16:32:21 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146090176 1863 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146090463 In 1863 English chemist John Newlands divided the then discovered 56 elements into 11 groups, based on characteristics.


]]> 2022-04-17 16:33:10 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146090463 1869 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146091070 In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.



]]> 2022-04-17 16:34:46 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146091070 1886 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146091894 In 1886 French physicist Antoine Bequerel first discovered radioactivity. Thomson student from New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. Marie and Pierre Curie started working on the radiation of uranium and thorium, and subsequently discovered radium and polonium. They discovered that beta particles were negatively charged.


]]> 2022-04-17 16:36:46 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146091894 1894 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146092919 In 1894 Sir William Ramsay and Lord Rayleigh discovered the noble gases, which were added to the periodic table as group 0.


]]> 2022-04-17 16:39:25 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146092919 1897 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146094130 In 1897 English physicist J. J. Thomson first discovered electrons; small negatively charged particles in an atom. John Townsend and Robert Millikan determined their exact charge and mass.


]]> 2022-04-17 16:42:23 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146094130 1900 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146098940 In 1900 Bequerel discovered that electrons and beta particles as identified by the Curies are the same thing.


]]> 2022-04-17 16:53:07 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146098940 1903 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146100210 In 1903 Rutherford announced that radioactivity is caused by the breakdown of atoms.



]]> 2022-04-17 16:55:47 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146100210 1911 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146100378 In 1911 Rutherford and German physicist Hans Geiger discovered that electrons orbit the nucleus of an atom.


]]> 2022-04-17 16:56:07 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146100378 1913 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146100773 In 1913 Bohr discovered that electrons move around a nucleus in discrete energy called orbitals. Radiation is emitted during movement from one orbital to another.


]]> 2022-04-17 16:56:53 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146100773 1914 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146101009 In 1914 Rutherford first identified protons in the atomic nucleus. He also transmutated a nitrogen atom into an oxygen atom for the first time. English physicist Henry Moseley provided atomic numbers, based on the number of electrons in an atom, rather than based on atomic mass.



]]> 2022-04-17 16:57:20 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146101009 1932 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146101290 In 1932 James Chadwick first discovered neutrons, and isotopes were identified. This was the complete basis for the periodic table. In that same year Englishman Cockroft and the Irishman Walton first split an atom by bombarding lithium in a particle accelerator, changing it to two helium nuclei.


]]> 2022-04-17 16:57:52 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146101290 1945 21900095 https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146102299 In 1945 Glenn Seaborg identified lanthanides and actinides (atomic number >92), which are usually placed below the periodic table.


]]> 2022-04-17 16:58:31 UTC https://padlet.com/21900095/nr496qy2y0uty1vs/wish/2146102299