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6000 BCE
Gold is (presumed) discovered
Gold is presumed discovered by Bulgarians. -
3750 BCE
Carbon is discovered
Carbon is used by Ancient Egyptians. -
499 BCE
Leucippus
Leucippus was a Greek philosopher, and the first to propose atomism, the idea that everything is consisted of various imperishable elements called atoms. -
490 BCE
Empedocles
Empedocles was an Ancient Greek philosopher, who started the old belief of the 4 elements, earth, wind, fire, and air. He also proposed love and strife, forces that could mix and separate the elements. -
460 BCE
Democritus
Democritus was born in Thrace, though his birthdate cannot be exactly confirmed, he was born around 460 BC. Thrace was an Ancient Greek country that is now modern day Bulgaria, Greece, and Turkey. Although his teachings are hard to differentiate from his mentor, he is known for being the philosopher who created the atomic theory. The theory states,
A) Atomos- that which cannot be cut
B) Definition of atom- smallest unit of matter which still retains the identity and property of that matter -
384 BCE
Aristotle
Aristotle was another Ancient Greek philosopher, who was born in Chalkidiki. He was born around 384. Aristotle disagreed with Democritus’ philosophy, and through that there was only 4 elements, Earth, Air, Fire, and Water. Since Aristotle refuted Democritus, it led to an almost 2000 year span of bogus science. -
340 BCE
Vitalism
Though when it started or who started it is not clear but, some people thought some of Aristotle’s beliefs were vitalist, so it can be traced somewhere around his era of philosophy. Vitalism was a short lived ideology that living and non living organisms are separated because non living organisms so not have a vital spirt, which living things did, which gave the living things the ability to make inorganic compounds. Although this ideology was proven wrong by many, causing up its downfall. -
332 BCE
Alexander the Great
Alexander the Great was a king of Greece, and was born in Pella in 356 BC. He took the throne at just age 20. He was tutored by Aristotle. Alexander the Great conquers Egypt in 332, the Greek philosophers became interested in the religion of Egypt, as their beliefs of 4 elements was similar to that of the Greeks. -
300 BCE
Alchemy
Alchemy is a philosophical ideology aiming toward the purification of metals. It started in Egypt after Alexander the Great conquered Egypt. The name derives from Khemia. This was the Greek word for Egypt. Khemia was the system of beliefs that Greece and Egyptian religion shared. -
600
Later Alchemy
In 600 A.D. Arabs occupied Egypt and developed the science. They eventually spread it farther to the west, in Spain. The belief bacame that all metals were made up of Mercury and Sulfur with varying levels of the amount. Gold is the highest purest metal, with everything else being a base. The basis of the belief was that you could purify these metals to be up to gold.
Later on, in the 16th century, the Alchemists split into 2 groups. -
600
Later Alchemy Cont.
In the West, the group focused on compounds, reactions, and chemical processes. This lead up to modern day chemistry. This group later went on to invent distillation, percolation, extraction, and rudimentary chromatography.
The other group focused on the same old belief that you could purify base metals into noble metals. They also searched for more metaphysical things like immortality. -
721
Jabir ibn Hayyan
Jabir ibn Hayyan was a Persian-Arabian philosopher who was known to have primarily refined and create the Medieval Alchemist system. He believed in they four basic elements, however he also believed in two other elements, which were Sulfur and Mercury. -
1493
Paracelsus
Paracelsus was a phisician, alchemist, and stroller born during 1493 in Sweden. He is known as the “father of toxicology”. He supported the 4 element theory, but saw them as 3 principles. He justified this by describing how fire burns wood. Although, he more known for his medical discoveries. -
1561
Francis Bacon
Francis Bacon was a man of many trades, he was a statesman, author, and juror, however, he was also a scientist and philosopher. Francis Bacon was born in 1561, and was later in his life known as Francis Bacon, 1st Viscount St Alban. And later, after his death, known as the father of empiricism (the theory that knowledge comes from sensory experience). He is known also for his books influencing the scientific method. -
Robert Boyle
Robert Boyle was born in 1627, and is given the title, the first modern chemist. He is known for playing part in modern chemistry. He is however best known for Boyle’s Law, a law that states that gas pressure increases as volume of container increases. He backs this up with how the lungs work, our lungs can increase in size, which meant an increase of pressure was present. -
The Phlogiston Theory- Johann Joachim Becher
The Phlogiston Theory was introduced in 1667 by Johann Joachim Becher. However, it was later evaluated by Georg Ernst Stahl. states that there is a fire-like element called Phlogiston contained within combustible bodies which is released during combustion. It also stated that anything that can combust has Phlogiston. Carbon Dioxide is one substance that, since was no longer capable of combusting, is considered dephlogisticated air. This belief ended up dying due to metals expanding when heated. -
Antoine Laurent de Lavoisier ~ “The Father of Modern Chemistry”
Lavoisier was born on August 26th, 1743. He was a French nobleman and chemist. He is known as the father of modern chemistry. He was central to the 18th century chemical revolution. Lavoisier relied on quantitative observation to develop conclusions. Dispelled the Phlogiston Therory by showing oxygen causes combustion. He discovered the law of Observation of mass. He stated mass of metal oxide=the mass of metal+oxygen when the metal oxide compresses. He was guillotined in the French Revolution. -
Benjamin Franklin
Benjamin Franklin was born in 1785, he was Avery important part of history, and to science. He had noted how conductivity works by putting a key on a kite and flying it in a storm. He discovered that electricity had a positive and negative charge. He also noted that on a hot day, he felt cooler in a wet shirt rather than a dry one, this was evaluating on refrigeration. -
Joseph Louis Proust
Joseph Louis Proust was born on September 26th, 1754. He discovered the law of Definate Proportions, aka, The Law of Constant Composition. This Law states that a chemical compound always contains exactly the same proportion of elements by mass. -
Hydrogen is discovered
Hydrogen is discovered by Henry Cavendish -
John Dalton
John Dalton, “The Father of Atomic Theory”, was born 1766. He was known for his theory of matter. This states, a) matter is made up of atoms that are indivisible and indestructible. B) all atoms of an element are identical (false). C) atoms of different elements have different weights and chemical properties. D) Atoms of different elements combine in simple whole numbers to form compounds. E) Atoms cannot be created or destroyed. When a compound decomposes, the atoms are recovered unchanged -
Oxygen is discovered
Oxygen is discovered by W. Scheele -
Uranium is discovered
Uranium is discovered by H. Klaproth. -
William Crookes
William Crookes was born in England in 1832. He is known for the crookes tube, which later was developed into the Cathlode Ray Tube. -
CRT
The Cathlode Ray Tube was discovered in Crookes Tubes. CRTs are 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 some type of radiation streaming from the battery (the cathode).
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. -
Ernest Rutherford
Known as the father of nuclear physics, established a nuclear structure and a classification of radiation.
He also did the gold foil experiment where he put gold foil over a tin can and painted the inside ofcan with florescent paint. Aimed alpha rays at the foil. -
Sir John Joseph Thomson
J. J. Thomson was born in 1896, and credited with the discovery of electrons. While experimenting with the CRT, he used charged plates to deflect the Cathlode away, he deduced that the ray deflected away from the plate, so it had a negative charge. He called the negative particles electrons. -
Becquerel
Along with Marie and Pierre Curie, discovered radioactivity in uranium ore. -
Marie and Pierre Curie
Marie and Pierre Curie were a married couple who discovered and isolated polonium and radium from uranium ores. They pioneered research upon radioactivity as well. -
Millikan
Robert Millikan was born in 1868. He is known for calculating the mass and charge of the electron in 1910. -
Period: to
Modern Atomic Theory
Modern atomic theory states that atoms are made up of three particles, protons, neutrons, and electrons. Atomic mass is the mass of protons or neutrons. Atomic number is the amount of protons in the nucleus. Mass number is the amount or protons and neutrons -
James Chadwick
Chadwick was born in 1891. He was known for discovering the neutron, a subatomic particle that has no charge. He was also the head of the British Manhattan project during WW2.
