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Period: 460 BCE to 370 BCE
Democritus
Democritus Came up with the original idea that within infinite space (or the ‘void’) an infinite amount of atoms are being moved around to create matter. He stated that atoms made up everything and were so small that they are unable to be cut, therefore the name atomon, or indivisible.
https://historyoftheatomictheory.weebly.com/aristotle.html -
Period: 384 BCE to 322 BCE
Aristotle
Aristotle’s main goal was to rebuttal the philosophical contributions to the atomic theory made by Democritus. He philosophized that the universe was not made up of small particles, and that everything was just one large mass. He also said that everything was just a combination of fire, water, air, and earth. By disagreeing with Democritus, Aristotle set modern atomic theory back by about 2000 years.
https://historyoftheatomictheory.weebly.com/aristotle.html -
Period: 300 BCE to 500 BCE
Alchemy Part 1
Alexander the Great had conquered Egypt, and Greek philosophers were now interested in Egyptian religion, and Aristotle’s view that everything is made of fire, earth, water, and air were merged with Egyptian religion. The result of this merge was ‘Khemia’ which is the Greek word for Egypt, and soon the word ‘Alchemy’ was created. In 391 most relevant Alchmey were completely burned when Christians set fire to a library Alexandria.
http://www.chm.bris.ac.uk/webprojects2002/crabb/history.html -
Period: 500 to 700
Alchemy Part 2
In 600 BC the arabs invaded Egypt and created the development of alchemy as well as spread it westward in the 700 BC. Many new ideas were distributed, including that all metals are made up of mercury and sulfur. Gold is the perfect and ideal metal and all others could be transformed using the philosophers stone. Alchemists supplied the theory of the perfect metals to humans and sought out perfect human conditions as well as spiritual purification and immortality -
Period: 1493 to 1541
Philippus Aureolus Paracelsu
Philippus Aureolus Paracelsu took a completely new look into alchemy and instead of looking into turning base metals into goal, looked into the medicinal purposes of alchemy. He also believed that the body is harmonious and when it becomes unbalanced you would get sick, so the balance needed to be restored. Source: https://en.m.wikipedia.org/wiki/Alchemy -
Period: 1500 to
alchemy part 3
in the 16th, century alchemists in Europe had finally separated into two groups. in the west, the alchemists focused on the actual science and spent time on the discovery of compounds, chemical processes, distillation, percolation, extraction, rudimentary chromatography. these processes lead to what is today chemistry. -
Period: to
Vitalism
starting back in ancient Egypt vitalism is the theory that all living organisms are fundamentally different from non-living entities because they contain a ‘vital spirit’, and living beings are governed by different principles than inanimate things. biologists started looking into vitalism and a discourse broke out, some saying that eventually the process of life would be explained through science, and others saying that was simply not the case Source: https://en.m.wikipedia.org/wiki/Vitalism -
Period: to
The Phlogiston Theory
the name for the theory originated from the Ancient Greek phlogistón, which translated to "burning up". The theory was first started in 1667 by Johann Joachim Becher. It postulated the existence of a fire-like element called "phlogiston", which was contained within combustible bodies and released during combustion.
Source : https://en.wikipedia.org/wiki/Phlogiston_theory -
Period: to
Antione de Lavoisier
Antione de Lavoisier was known as the father of modern chemistry because instead of using philosophy, he relied on quantitive observations to come to a conclusion. he was responsible for the dispersal of the phlosion theory by proving that oxygen causes combustion. -
Period: to
Benjamin Franklin
Benjamin Franklin believed that when rubbing two substances together, the fluid would change location. Franklin also Discovered that electrical charges come in 2 varieties, positive and negative. Like charges repel, opposite charges attract.
https://en.m.wikipedia.org/wiki/Electric_charge -
Period: to
Joseph Louis Proust
Proust created the Law of Definite Proportions, sometimes called The Law of Constant Composition, states that a chemical compound always contains exactly the same proportion of elements by mass. H2O always contains 88.9% O, 11.1% H by mass. Proust studied copper carbonate, the two tin oxides, and the two iron sulfides to prove this law. He did this by making artificial copper carbonate and comparing it to natural copper carbonate. -
Period: to
John Dalton
John Dalton is known as the father of the modern atomic theory because of his creation of Dalton’s Atomic Theory of Matter. The theory stated that Matter is made up of atoms that are indivisible and indestructible, All atoms of an element are identical, which is now disproved, Atoms of different elements have different weights and different chemical properties, Atoms of different elements combine in simple whole numbers to form compounds, and Atoms cannot be created or destroyed. -
Period: to
William Crookes et. al.
When Crookes placed a paddle wheel in the CRT and turned on the battery, the wheel spun. Since the tube was evacuated, this told Crookes that the Cathode Ray has mass. -
Period: to
Sir John Joseph Thomson
Sir John Joseph Thomson continued experimenting on the CRT. JJ Thomson used charged plates to deflect the cathode ray. Found the ray deflected away from the negative plate, and toward the positive. He Deduced that the cathode ray was made of Negative particles. He named them electrons. -
Period: to
Antoine Henri Becquerel
Antoine Henri Becquerel discovered radioactivity in uranium. -
Period: to
Curies
Curies Discovered and isolated polonium and radium from uranium ores. The study of radioactive elements gave scientists the inkling that there had to be something inside the atom that gave it its identity, and that if that thing changed, the atom would change or “transmute” into another element. -
Period: to
Robert Andrews Millikan
Robert Andrews Millikan Calculated the mass and charge of an electron. -
Period: to
James Chadwick
James Chadwick Proved the existence of another subatomic particle, that had no charge, named it the neutron.