-
460 BCE
Democritus
Deomocritus was an Ancient Greek philosopher who is known for his formulation of an atomic theory of the Universe. The theory of Democritus was that everything is made up of “atoms” which is physically indivisible thus atoms are indestructible and have always and will always be in motion. -
384 BCE
Aristotle
Aristotle is an Ancient Greek Philosopher and is considered to be known as the “Father of Western Philosophy”. Aristotle’s philosophy aims towards the universe and is based on the study of things that exist or happen in the world. He believes in earth, air, fire, and water. -
332 BCE
Alexander the Great
Alexander the Great studied under Aristotle at the age of 16. He then took over his Father’s throne and spent most of his ruling years on an unprecedented military campaign through Asia and northeast Africa. Alexander the Great conquered Egypt in 332 BC, 4 years after taking the throne. -
300 BCE
Alchemy: part 1
Greek philosophers became interested in the Egyptian religion. Greek views of how matter is made up of the four elements of nature were merged with Egyptian religion. The result was Khemia, the Greek word for Egypt, which then aspired the word Alchemy. By the 16th century, the alchemist in Europe separated into 2 groups. -
300 BCE
Alchemy: part 2
In the West, they focused on the discovery of compounds, reactions, and chemical processes which led to the science of chemistry. The West also invented distillation, percolation, extraction, and rudimentary chromatography. The second group looked at the more spiritual side of alchemy. They continued the search for immortality and the transmutation of base metals into gold which then led to the modern day idea of alchemy. -
Vitalism
Vitalism states that living organisms are fundamentally different from non-living entities because they contain some non-physical element or have different principles than inanimate things do. Non-living things contain what is called a “Vital Spirit”. -
The Phlogiston Theory
The Phlogiston Theory was first stated by Johann Joachim Becher in 1667. This theory stated that the existence of a fire-like element called "phlogiston",which was contained within combustible bodies and released during combustion.The theory attempted to explain processes of combustion, which is now collectively known as oxidation. -
Anton La Voiser
Anton La Voiser was known as the Father of Modern Chemistry because he relied on quantitative observation to develop conclusions. He also disproved the Phlogiston Theory by proving that Oxygen can cause combustion. He also discovered the Law of Conservation of Mass by proving that the mass of a metal oxide is equal to the mass of the metal plus oxygen when the metal oxide decomposes.Thus matter can change form, but cannot be created nor destroyed in a chemical reaction. -
Benjamin Franklin
Franklin was a leading author, printer, political theorist, politician, freemason, postmaster, scientist, inventor, humorist, civic activist, statesman, and diplomat. He discovered that electrical charges come in 2 varieties, positive and negative. The same charges repel, and opposite charges attract. Benjamin invented many objects like the lightning rod, a glass harmonica, the Franklin stove, bifocal glasses, and the flexible urinary catheter. -
Joesph Louis Proust
Proust was a French Chemist who founded the Law of Definate Proportions, also known as the Law of Constant Composition, which states that a chemical compound always contains the exactly same proportion of elements by mass. -
John Dalton
He was known as the Father of Atomic Theory. His theory of matter stated: Matter is made up of atoms that are indivisible and indestructible, all atoms of an element are identical(not true now), 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. When a compound decomposes, the atoms are recovered unchanged. -
William Crookes
He was a British chemist and physicists. William Crookes invented many things but mainly the Cathode Ray Tube (CRT). The CRT was a glass tube that is evacuated (contains no air or matter) coated with fluorescent paint. When connected to a battery, the paint glows, indicating that there is radiation streaming from the battery. 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. -
Sir John Joesph Thomson
He continued the experiment of the CRT after Crookes. Thomson used charged plates to deflect the cathode ray and found that the ray deflected away from the negative plate, and toward the positive. Thus concluded that the cathode ray was made up of electrons, negative particles. -
Ernst Rutherford
Ernst Rutherford formed the classification of radiation with the Famous Gold Foil Experiment. He Stretched a sheet of gold foil in a tin can and coated the inside of the can with fluorescent paint. He then aimed a ray of alpha radiation at the foil. He expected that fluorescent coating would light up right behind the foil. He observed that 99.9% of the time, the ray lit up the can right behind the foil. This told him that the ray had hit something massive and dense in the center of the atom. -
Becquerel
The becquerel is named after Henri Becquerel, who shared a Nobel Prize in Physics with Pierre and Marie Curie in 1903 for their work in discovering radioactivity in Uranium ore. -
Marie and Pierre Curies
Marie Currie was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. Pierre Currie was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity and radioactivity. Together they discovered and isolated polonium and radium from uranium ores. -
Robert Andrews Millikan
Millikan was an American experimental physicist honored with the Nobel Prize for Physics, for the measurement of the elementary electric charge, and for his work on the photoelectric effect. He calculated the mass and charge of an electron. -
James Chadwick
James Chadwick was a British physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron. He proved the existence of another subatomic particle, that had no charge, named it the neutron.
