https://padlet.com/ecalaycay0023/jiyqofnmelork2b2 This timeline is a short/quick recap of "who" and "what" has contributed in the study of the "Atomic Theory". These people and studies has lead us to the present idea of an Atom! en-us 2022-01-30 07:33:47 UTC 2025-11-02 00:36:39 UTC hello@padlet.com https://padlet-uploads.storage.googleapis.com/1142756667/64deeb5b28ede078b37bd82fbdf7113e/science.png ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024730781 Picture of Democritus]]> 2022-02-02 05:30:26 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024730781 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024733294 An Ancient Greek Philosopher in 400 BCE, Democritus proposed the idea of the Atomos. It is a matter that consists of very small and indivisible objects which couldn't be broken down any further. He believed this couldn't be seen by the naked eye as it was made up of tiny particles. His ideas were rejected at first because of the opposition made by Aristotle who believed matter was made up of the four natural elements. It took about 2000 years before his concept reemerged. ]]> 2022-02-02 05:33:45 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024733294 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024737481 He was an English Physicist & Chemist back in the early 1800s who proposed the first atomic theory after conducting a number of experiments. After performing these experiments, his ideas eventually led to the acceptance of the idea of atoms. He wrote this in his book, A New System of Chemical Philosophy. ]]> 2022-02-02 05:39:00 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024737481 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024894368 2022-02-02 08:16:23 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024894368 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024946402 2022-02-02 08:55:37 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2024946402 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028762656

He deduced that all elements are composed of atoms. Atoms are indivisible and indestructible particles

Atoms of the same elements are exactly alike

Atoms of different elements are different

Compounds are formed by the joining of atoms of two or more elements

]]> 2022-02-04 03:22:32 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028762656 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028764521 2022-02-04 03:24:07 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028764521 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028765762 2022-02-04 03:25:24 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028765762 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028769813 2022-02-04 03:29:16 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028769813 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028775422 The English Scientist, Joseph John Thomson, provided the first hint that an atom is made of even smaller particles back in 1897. He conducted an experiment called "The Cathode Ray Experiment" and also showed the "Plum Pudding" model for his interpretation of an atom.]]> 2022-02-04 03:35:11 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028775422 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028778837 J.J Thomson tried applying high electric voltage at either end of the tube between two electrodes. He then observed a particle stream (ray) coming out of the negatively charged electrode (cathode) to the positive charged electrode (anode). This ray is called cathode ray. ]]> 2022-02-04 03:39:03 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028778837 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028782144 2022-02-04 03:42:34 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028782144 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028786895 He believed an atom is a positively-charged structure with negatively-charged electrons scattered about, like plum (or raisins) in a pudding 

]]> 2022-02-04 03:47:04 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028786895 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028788275 2022-02-04 03:48:19 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028788275 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028791500 2022-02-04 03:51:18 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028791500 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028794535 2022-02-04 03:54:30 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2028794535 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031084999 In 1908, Ernest Rutherford who is a New Zealand physicist performed his contribution by conducting the "Gold Foil Experiment" and also discovered another important subatomic particle.]]> 2022-02-06 02:45:42 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031084999 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031085432 This experiment of Rutherford involved firing a stream of tiny positively-charged particles at a thin sheet of gold foil (2000 atoms thick). ]]> 2022-02-06 02:46:53 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031085432 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031085844

Most of the alpha particles passed through the gold foil with little or no deflection.

A few alpha particles were deflected at large angles.

A few other alpha particles bounced back.

]]> 2022-02-06 02:48:02 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031085844 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031087841 2022-02-06 02:53:59 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031087841 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031088350 2022-02-06 02:55:35 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031088350 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031090252 In Rutherford's nuclear atom, protons and neutrons (comprises nearly all of the mass of the atom) are located in the nucleus, which is at the center of the atom. Meanwhile the electrons are located outside the nucleus, and occupy most of the volume of the atom (which is mostly an empty space).

]]> 2022-02-06 03:01:45 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031090252 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031090726 2022-02-06 03:03:11 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031090726 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031093238 2022-02-06 03:10:41 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031093238 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031094309 Danish scientist, Niels Bohr proposed an improvement to the past Atomic Models. In his model that he made in 1913, he placed each electron in a specific energy level. ]]> 2022-02-06 03:13:56 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031094309 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031095483 2022-02-06 03:15:56 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031095483 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031095755 Since electrons move in definite orbits around the nucleus, much like planets circle the sun. These orbits or energy levels that Niels Bohr has adjusted, are located at certain distances from the nucleus.]]> 2022-02-06 03:16:44 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031095755 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031096987 2022-02-06 03:20:44 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031096987 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031099451 2022-02-06 03:27:31 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031099451 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031101898 Back in 1926, Austrian-Irish physicist, Erwin Schrödinger took the Bohr atom model one step further. He used mathematical equations to describe the likelihood of finding an electron in a certain position. ]]> 2022-02-06 03:34:16 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031101898 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031102368 2022-02-06 03:35:39 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031102368 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031103583 Comparing from Bohr's model, the Quantum Mechanical model does not define the exact path of an electron, but rather, predicts the odds of the location of the electron. ]]> 2022-02-06 03:39:08 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031103583 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031103994 Erwin Schrödinger's Atomic Model: The Quantum Mechanical Model]]> 2022-02-06 03:40:22 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031103994 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031105001 2022-02-06 03:43:08 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031105001 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031106176 In 1932, James Chadwick noticed an unfamiliar radiation that was produced with the atoms. He noticed this after placing a bunch of beryllium atoms with alpha particles, and later on he interpreted this radiation as being composed of particles with a neutral electrical charge and the approximate mass of a proton. This interpretation of his has led him in proving the existence of a neutron.]]> 2022-02-06 03:46:01 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031106176 ecalaycay0023 https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031108401 2022-02-06 03:52:21 UTC https://padlet.com/ecalaycay0023/jiyqofnmelork2b2/wish/2031108401