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1743 BCE
Anton La Voisier
-Father of Modern Chemistry because he relied on quantities observation to develop conclusions
-Dispelled the Phlogiston Theory by proving that oxygen causes combustion
-Discovered the Law of Conservation of Mass: By proving that the mass of a metal oxide = the mass of the metal plus oxygen when the metal oxide decomposes
-Matter can change form, but cannot be created nor destroyed in a chemical reaction
-Is most noted for his discovery of the roleoxygen plays in combustion -
1667 BCE
The Phlogiston Theory
-From the Ancient Greek phlogiston “burning up”
-First started in 1667 by Johann Joachim Becher
-Postulated the existence of a fire-like element called “phlogiston”, which was contained within combustible bodies and released during combustion
-A substance that burned and did so because it contained Phlogiston
-Carbon Dioxide, no longer capable of burning was called “dephlogisticated air”
-The prevailing theory was that flammable materials contained a substance called Phlogiston -
1600 BCE
Vitalism
Definition of Vitalism: the theory that the origin and phenomena of life are dependent on a force or principle distinct from purely chemical or physical forces.
Living organisms are fundamentally different from non-living entities because they contain some non-physical element or are goverened by different principles that are inanimate things. -
1500 BCE
Alchemy Part 3
The alchemists in Europe had separated into two groups: western alchemists focused on the discovery of new compounds, reactions, and chemical processes leading to what is now the science of chemistry. Invented Distillation, percolation, extraction, rudimentary chromatography. The second group continued to look at the more spiritual, metaphysical side of alchemy, continuing the search for immortality and the transmutation of base metals into gold. This led to the modern day idea of alchemy. -
600 BCE
Alchemy Part 2
-Arabs occupied Egypt and further developed the science, spread it to the West (Spain) in 700’s
-Metals are made up of mercury and sulfur in varying proportions
-Gold is the perfect metal and all others were “Baser” metals, capable of being transmitted into gold by means of a substance known as the Philosophers Stone
-Alchemists applied this concept of purification and search for perfection to the human condition, and sought spiritual purification and immortality -
460 BCE
Democritus
He was an influential Ancient Greek philosopher who was born in Abdera, Thrace. Democritus was known for his formulation of an atomic theory. His mentor was Leucippus and together they discovered the first atomic theory on January 1st. The word atom comes from the word “atomos”, which means indivisible.
Atomos: that which cannot be cut
Definition of Atom: the smallest unit of matter which still retains identity and properties of that matter -
384 BCE
Aristotle
-Born in Stagire, Greece
-Enrolled in Plato’s Acedemy at age 17
-Started tutoring Alexander the Great in 338
-Founded his own school, the Lyceum
-Studied, taught, and wrote at the school he founded
-Didn’t believe in the atomic theory
-Refuted Democritus
-Believed in four elements: Earth, Air, Fire, and Water
-Aristotle’s refutation of Democritus’ Atomic Theory led to nearly 2,000 Year’s of bogus “science” among the most prominent: -
300 BCE
Alchemy Part 1
-332 BC Alexander the Great had conquered Egypt
-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
-The word Alchemy came from the word Khemia, which means Egypt -
Benjamin Franklin
-Discovered that electrical charges come in 2 varieties-positive and negative
-Like charges repel, opposite charges attract
-Invented the lightning rod, bifocals, the Franklin Stove, and a lot more
-Was a founding father of the United States -
Joseph Louis Proust
-The Law of Definite Proportions, sometimes called The Law of Comstant 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
-Was a French chemist
-Discovered grape sugar -
William Crookes
A. Cathode Ray Tube (CRT)
CRT - 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)
B. Paddle wheel placed in CRT:
When Crookes placed a paddle wheel in the CRT and turned on the battery, the wheels spun. Since the tube was evacuated, this told Crookes that the Cathode Ray has mass
-Was an English chemist and physicist -
Sir John Joseph Thomson
A. 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
B. Deduced that the cathode Ray was made of:
Negative particles. He named them electrons
-Was an English physicist
-Was a Nobel laureate in physics
-Discovered and identified the electron
-Discovered the first subatomic particle -
Curies (Marie and Pierre)
-Discovered and isolated polonium and radium from uranium ores.
-The study of radioactive elements (elements that spontaneously change into different elements due to instability) gave scientists the inkling that there had to be something inside the atom.
-Was a Polish and naturalized-French physicist and chemist.
-Conducted pioneering research on radioactivity.
-Were awarded the 1903 Nobel Prize in physics. -
Becquerel
-Was a French physicist, Nobel laureate, and the first person to discover evidence of radioactivity
-Discovered radioactivity in uranium ore -
Milikan
-Calculated the mass and charge of an electron
-Was an American experimental physicist
-Got the Nobel Prize for physics in 1923 for the measurement of the elementary electronic charge and for his work on the photoelectric effect -
James Chadwick
-Proved he existence of another subatomic particle, that had no charge, named it the neutron
-Was an English physicist
-Was awarded the 1935 Nobel Prize in physics
-Discovered the neutron in 1932
-Was born in Cheshire, England