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3750 BCE
The history of Carbon
Although Carbon has been around practically since the earth began, the first solid evidence of its existence appeared around 3750 BCE. This evidence came in the forms of soot and charcoal that were left by ancient civilizations. In terms of carbons properties, it has the ability to bind with a large variety of other elements due to it possessing four valence electrons. Also carbon has many allotropes (forms) with two of the more common allotropes being diamond, and graphite. -
3000 BCE
The History of Gold
Like carbon, gold is seen throughout humanities history.The first real evidence of human interaction with gold however was in Ancient Egypt around 3,000 BC. Gold was very important within Egyptian mythology and was highly coveted by both pharaohs and priests within Egypt. Such was the extent of the Egyptians love for gold that they made the capstones on the pyramids of Giza. Gold itself is the most malleable and ductile metal, and is a good conductor of thermal energy and electricity. -
Period: 460 BCE to 370 BCE
Democritus
Democritus was an ancient Greek philosopher known today for his formulation of atomic theory. Democritus was responsible for naming of the atom, deriving from the word “atomos” which means “that which cannot be cut. An atom is the smallest unit of matter which still retains the identity and properties of said matter -
Period: 384 BCE to 322 BCE
Aristotle
Aristotle was an ancient Greek philosopher and scientist who is considered to be the father of Western Philosophy. In his time Aristotle refuted Democritus’ claims about atomic theory. His refutation of Democritus’ theory led to almost 2000 years of so called “bogus” science. Aristotle himself believed there were four elements, earth, air, fire and water. -
332 BCE
Alexander’s conquest
In 332 BC Alexander the Grrat conquered Egypt, thus introducing the Greeks to many Egyptian ideas, and which also sparked an interest in the Egyptian religion by the Greeks. This interest resulted in the word “Khemia”, which is the Greek word for Egypt. From this word eventually came the word Alchemy. -
300 BCE
Alchemy
Alchemy was the medieval predeccesor to chemistry, being based on the transformation of matter. Transformations of particular interest to alchemists were the transformations concerning the attempt to convert base metals into gold. -
600
The Arab conquering of Egypt
Arabs eventually overtook Egypt from the Greeks and further developed the science present there. Eventually, the science of Egypt spread into the west (Spain) in the 700s. -
1501
Division of European Alchemy
By the 16th century, alchemists in Europe split into two different groups. The group in the West focused on discovering new compounds, reactions, and chemical processes. These alchemists also invented distillation, percolation, extraction, andrudimentary chromatography. This groups work eventually lead to what is modern day chemistry. The second group focused on the Mystic side of chemistry, such as finding immortality, or transmuting base metals into gold. This group led into modern Alchemy. -
Period: to
Vitalism
Vitalism is the belief that living organisms are fundamentally different than non living things as they contain a “vital spirit”. Due to this belief, living things are regarded with different principles than non living things. Over the years vitalism has fallen out of favor, however it still ha advocates, even into the twentieth century. One of the most if not the most notable of these advocates was an embryologist named Hans Driesch. -
The Phlogiston Theory
The word Phlogiston comes from the Ancient Greek word phlogistón, which means “burning up” and was first stated in 1667 by Johann Joachim Becher, a German physicist. The theory itself suggests that a fire-like element called phlogiston exists and is found inside combustible bodies, and is released when said body combusts. The theory also suggests that a substance that burned was able to do so as it contained phlogiston. Also, carbon dioxide that cannot be burned is called dephlogisticated air. -
Period: to
Benjamin Franklin
Benjamin Franklin was a scientist, inventor and is honored as one of the founding fathers of America. In terms of chemistry, Franklin is most known for discovering that electrical charges appear in two forms, positive and negative respectively. Like electrical charges repel from each other, while opposites attract -
Period: to
Henry Cavendish
Henry Cavendish was a British philosopher, chemist, and physicist who is most known for his discovery of Hydrogen in 1766. Cavendish is also known for his “Cavendish” experiment, in which he measured the force of gravity between masses in his laboratory. This was the first experiment to give accurate values for gravitational constants. -
Period: to
Anton Laurent La Voisier the Father of Modern Chemistry
Antoine was a French chemist who was central to the chemical renaissance, and is regarded as the father of modern chemistry, as he relied on quantitative observations to form conclusions. Antoine also dispelled the phlogiston theory after proving that combustion relies on oxygen. Also he proposed the law of mass as he found that a metal oxide equals the mass of a metal plus oxygen when the metal oxide decomposes. He also said that matter cannot be created or destroyed in a chemical reaction. -
Period: to
Daniel Rutherford
Daniel Rutherford was a Scottish chemist, physician, and botanist known for his isolation of nitrogen in 1772. When Rutherford’s mentor, Joseph Black was studying carbon dioxide he noticed a candle could not burn in it, and turned it over to Rutherford to investigate. Rutherford kept a mouse in a space with a confined quantity of air until it died. Then, he burned a candle in the remaining air until it went out. He then put that air through a carbon absorbing solution and nitrogen remained. -
Period: to
Joseph Louis Proust
Joseph Louis Proust was a French Chemist who is best known for his discovery of the law of constant composition/the law of definite proportions. The law states that a chemical compound always contains exactly the same proportion of elements by mass, for instance, H2O always contains 88.9% O, 11.1% H by mass. -
Discovery of Hydrogen
Hydrogen was officially recognized in 1766 by British scientist Henry Cavendish. Cavendish recognized hydrogen as a discrete substance, and named it hydrogen or “inflammable gas”. -
Period: to
John Dalton the Father of Atomic Theory P.1
John Dalton was an English chemist who is best known for introduction of Atomic theory Dalton declared that matter is made up of atoms which are indivisible and indestructible. He also stated that all atoms of an element are identical, however this was found to be untrue. Dalton also said that atoms of different elements have different weights and chemical properties. -
Period: to
John Dalton the Father of Atomic Theory P.2
Dalton also discovered that atoms of different elements combine in simple whole numbers to form compounds. Lastly, Dalton discovered that atoms can’t be created or destroyed, and that when a compound decomposes the atoms are recovered unchanged -
Discovery of Uranium
Uranium was discovered in 1789 by Martin Heinrich Klaproth who named the ore after the newly discovered planet Uranus. The first person to isolate this newly found metal was Eugène-Melchior Péligot, who also discovered its radioactive characteristics. -
Period: to
Sir William Crookes
Sir William Crookes was a British chemist, and physicist most known for his work on cathode rays and his invention, the Crookes Tube. A CRT (cathode ray tube) is a glass tube that is evaporated (contains no oxygen or matter) and is coated in fluorescent paint. When connected to a battery, the paint glows, which shows there is a type of radiation coming from the battery (cathode). Crookes put a paddle wheel inside a CRT, and when he turned the battery on the wheel spun, meaning the Ray had mass. -
Period: to
Antoine Henri Becquerel
Antoine Henri Becquerel was a French physicist who is most known for his discovery of radioactivity. In 1903 Becquerel discovered radioactivity within uranium ore, and the SI unit of radioactivity is named Becquerel after him. -
Period: to
Sir John Joseph Thompson
Sir John Joseph Thompson was an English physicist who is credited with the discovery of the electron, and the first subatomic particle, and who continued to work on the CRT. When Thompson was working on the CRT he used charge plates to deflect the ray, and found that the ray deflects from negative plates and towards to positive. From this experiment he realized that the cathode ray was made up of negative particles, and named them electrons -
Period: to
Pierre Curie
Pierre Curie was a French phycisist and the husband of Marie Curie, a fellow physicist. Together with Marie he discovered and isolated polonium, and also discovered radium from uranium ore -
Period: to
Marie Curie
Marie Curie was a Polish Physicist and wife of fellow physicist Pierre Curie. Alongside her husband she discovered and isolated polonium and discovered radium from uranium ore. -
Period: to
Robert Andrews Millikan
Robert Andrew Millikan was an American physicist known for his measurement of the elementary electric charge and work on the photoelectric effect. In 1910 Millikan was the first person to calculate both the mass and charge of an electron . -
Period: to
Ernest Rutherford
Ernest Rutherford was a British nuclear physicist known today as the father of Nuclear Physics. Rutherford classified Radiation in the year 1900 and conducted his famous Geiger-Marsden experiment in 1910. In this experiment he stretched a gold foil sheet in a tin covered with fluorescent paint and aimed a ray of positive radiation at the foil. He bought it would go throug but some of the particles were deflected. This meant that although atoms are mostly empty there’s a positively charged core. -
The Crookes tube
See Sir William Crookes -
Period: to
James Chadwick
James Chadwick was an English physicist who was granted the nobel prize in physics for discovering the neutron. Chadwick proved the existence of the neutron in 1932 and named it the neutron, taking inspiration from the word neutral, as it had a Neutral charge. -
Ernest Rutherfords gold experiment
See Ernest Rutherford -
Discovery of the proton
After Ernest Rutherfords discovery of the atomic nucleus in 1911, Antonius van den Broek proposed that the placements of the elements on he periodic table (its atomic #) is equal to its nuclear charge. This was later proven ivy Henry Moseley in 1913 by using X-ray spectra. Finally in 1917, Rutherford proved that the hydrogen nucleus is present in other nuclei, an achievement which is described as the discovery of protons.
