Historical timeline of the development of Atom and Element by 呂秀芳Regalado, Karylle Victoria https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk en-us 2022-01-09 07:18:40 UTC 2022-01-09 07:33:45 UTC hello@padlet.com Ideas of the Ancient Greeks on the atom karylleregalado https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982112034 Democritus believed that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped. Differences in atomic shape and size determined the various properties of matter.]]> 2022-01-09 07:23:46 UTC https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982112034 Ideas of the Ancient Greeks on the elements karylleregalado https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982113754 The ancient Greeks believed that there were four elements that everything was made up of: earth, water, air, and fire. This theory was suggested around 450 BC, and it was later supported and added to by Aristotle. The elements were “pure” but could not be found in that state on earth.]]> 2022-01-09 07:27:32 UTC https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982113754 Contributions of J.J.Thomson, Ernest Rutherford, Henry Moseley, and Niels Bohr to the understanding of the structure of the atom karylleregalado https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982115893 Thomson's model of the atom did explain some of the electrical properties of the atom due to the electrons, but failed to recognize the positive charges in the atom as particles. In 1911, Ernest Rutherford, a former student of J.J. Thomson, proved Thomson's plum pudding structure incorrect. Ernest Rutherford is known for his pioneering studies of radioactivity and the atom. He discovered that there are two types of radiation, alpha and beta particles, coming from uranium. He found that the atom consists mostly of empty space, with its mass concentrated in a central positively charged nucleus.]]> 2022-01-09 07:32:22 UTC https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982115893 Contribution of John Dalton toward the understanding of the concept and discovery of the chemical elements karylleregalado https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982116438 Dalton: John Dalton (1766-1844) was a chemist who developed the modern atomic theory and researched color blindness. Discovered a way to find the atomic weight of elements namely Hydrogen, Oxygen, Nitrogen, Phosphorus, Carbon and Sulfur. He also developed Dalton's Law which is the law of partial pressures.]]> 2022-01-09 07:33:41 UTC https://padlet.com/karylleregalado/bs7cm7cxrj98u7kk/wish/1982116438