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460 BCE
Democritus
Democritus was a Greek philosopher who is believed to be from Abdera Democritus's atomic theory was that all matter consists of atoms, atoms are extremely small-too small to see, atoms are solid particles that are indestructible, and atoms are separated by from one another by emptiness, or "void". Democritus made this theory up by mostly speculation, and by observing the world around him. This theory was and is still a huge contribution to the study of atoms, as most of it is correct. -
384 BCE
Aristotle
A Greek philosopher and scientist born in Stagira,Greece. And one of Plato's students. Upon the discovery of the atomic model, he refused to believe it and chose to believe that all substances were made of the five elements. Aristotle and his idea of 5 elements caused the acceptance of the atom to be delayed for about 2000 years. -
721
Abu Musa Jabir ibn Hayyan
Abu Musa Jabir ibn Hayyan is born somewhere in Iran. He is considered to be maybe the most influential alchemist of all time. -
771
Method Balance
Abu Musa Jabir ibn Hayyan
systematized a “quantitative” analysis of substances. He made major contributions to Jabirian Corpus. The Jabirian Corpus presented the "method of balance". This gave each letter of the Arabic Alphabet a numerical value. And these letters would be used to describe the quantity of the "four natures(hot,cold,wet and dry)" in an object. He also vectored the theory that the known metals are made of sulfur and mercury, by doing extensive experimentation. -
1200
St. Albertus Magnus is born
St. Albertus Magnus was a Dominican Bishop, scientist, and philosopher who was born around 1200 in Germany. -
1245
Science is included in the Christian Faith
He began working on his "Physica", which was to make the natural sciences "make sense to the Latins". "Physica" was written in order to convince the church that natural sciences were not against the faith but one could be learned in both. His contribution to science is that he made the study of nature a legitimate science within the Christian tradition. This would lead to more study on natural sciences especially by faithful Christians. -
1440
The printing press
The printing press was invented in the Holy Roman Empire by the German Johannes Gutenberg around 1440. The reason it was important is it allowed ideas scientific results to be mass produced and thus ideas and information spread faster, and people did not waste time testing the same thing in two different regions. -
Boyle is born
The 14th child of the earl of Cork known most for his development of Boyle's law. Robert Boyle was a scientist born in Ireland. -
Vacuum tube and electrostatic generator
In 1654 von Guericke invented a vacuum pump consisting of a piston and an air gun cylinder with two-way flaps designed to pull air out of whatever vessel it was connected to, and used it to investigate the properties of the vacuum in many experiments. The use of his vacuum in experiments was revolutionary. He also invented the first electrostatic generator which was made of a sulphur ball which rotated in a wooden cradle. This also helped with many future experiments involving atoms early on. -
The Sceptical Chymist
In his book The Sceptical Chymist he argued it was impossible to extract the four greek elements from a substance and it was impossible to form a substance using the four elements.
Boyle noticed that substances could be broken down into a simpler state. This lead to the conclusion that there are chemical substances (elements) that cannot be decomposed. -
NEW LAW
Boyle's law. Pressure and volume have an inversely proportional relationship. -
Cavendish
Henry Cavendish was an English physicist and chemist who was born in Nice, France. -
Birth of Lavoisier
A french chemist born in Paris, France. Who was later executed by the guillotine also in Paris, France. He is known as the first person to make use of the balance.Throughout his lifetime he would name the element carbon, hydrogen, and oxygen. He also discovered the role of oxygen during combustion. -
Dalton is born
A chemist, physicist, and meteorologist born in the United Kingdom. -
NEW LAW
Lavoisier announced a new law of nature, the law of conservation of mass. -
And here comes a mole
Avogadro was a chemist born in Turin, Italy known most for his contributions to molecular theory. -
Water everywhere
Henry's biggest contribution to science was the discovery and his descriptions of the properties of hydrogen, as well as the discovery that is was a constituent element in water. Besides his discovery another important part if his discovery is the way he went about experimenting this. He used gases like oxygen and put them into an electrostatic machine to experiment, this provided more results than previous experiments. -
Explosions now
Lavoisier found out that oxygen made up about 20% of the air and was necessary for combustion -
More on partial pressure
Dalton wanted to find the pressure of steam at different temperatures. He used 0 and 100 degrees Celsius. Upon his observation, he noted that the difference of vapor pressure for all liquids were equivalent for the same temperature. He then observed that for any given expansion of Hg(he was using a mercury thermometer so expansion in Hg just means increase in temp), the expansion of air is proportionally less as the temperature goes up -
NEW LAW
Dalton's Law of partial pressure-in a mixture of non-reacting gases, the total pressure exerted is equal to the sum of the partial pressures of the individual gases. -
Dalton's model
Dalton proposes an atomic model based on the assumptions such as, all atoms of an element are identical, atoms can neither be created or destroyed; atoms of different elements have different weights and properties; a compound is composed of different elements, and matter is made up of indestructible atoms. -
Period: to
Dalton for the history books
Dalton publishes his book A New System of Chemical Philosophy, where he explains atoms of different elements could be differentiated via their atomic weights.
1810: He publishes the appendix for A New System of Chemical Philosophy where he listed atomic weights of all known elements. -
Moles everywhere
Avogadro hypothesized that equal volumes of gases at the same temperature and pressure contain equal number of molecules
His hypothesis was ignored until it was proved correctly and published decades later. -
Mendeleev
A chemist born in Tobolsk, Russia. -
Sir William Ramsay is born
William Ramsay was a British Physical Chemist, born in Glasgow, Scotland. -
Thompson
The English physicist known most as the first person to discover a subatomic particle, the electron. He was born in Cheetham Hill, United Kingdom. -
Pierre Curie
French physicist born in Paris, France in 1859. -
More moles
Cannizzaro uses Avogadro's hypothesis to develop a set of atomic weights based on 1/16 of the atomic weight of oxygen. This would lead to more precise measurements of Avogadro's number -
Marie Curie is born
A chemist born in Warsaw, Poland -
AND WE HAVE A TABLE
Mendeleev created the periodic table of elements. He made sure to leave room for future elements which he had already predicted their atomic masses and chemical properties. -
Ernest Rutherford is born.
Ernest Rutherford was the central figure in the study of radioactivity. He was born in New Zealand. -
Lise Meitner is born.
Lise Meitner was a Jewish scientist who was born in Vienna, Austria. She worked closely with Otto Hahn. -
The birth of Niels Bohr
A physicist born in Copenhagen, Denmark. He worked under JJ Thompson -
The infamous cat in a box
Schrodinger was a Nobel prize winner born in Vienna, Austria -
James Chadwick is born
A physicist born in Cheshire, England -
De Broglie is alive
The first winner of the Poincare medal. De broglie was a french physicist born in Dieppe. -
Irene Joliot-Curie
A Nobel prize winner born in Paris, France -
NEW DISCOVERY
Thompson performed a range of test in order to study the nature of electric discharge in a high vacuum cathode-ray tube. He then interpreted deflected rays via electrically charged plates and magnets as evidence of something smaller than an atom. This unnamed thing was calculated to have a large ratio of charge to mass. This would later be called the electron. -
The Noble Gases?
Sir William Ramsay discovered four elements: argon, neon, krypton, and xenon. He showed that these four gases as well as helium and radon formed an entirely family of new elements, the noble gasses. This of course is quite important in chemistry and in the study of matter because four new things that make up matter were discovered. -
He´s probably alive
Heisenberg was a German theoretical physicist born in Würzburg, Germany. Heisenberg brought mathematics into the atomic model when he calculated the behavior of electrons and other subatomic particles within the atom. His work led to the development of the notion of an electron cloud. He also contributed quantum mechanics to the atomic theory. -
Linus Pauling is born
Linus Pauling was a teacher of quantitative analysis and scientist. He was born in Portland, Oregon. -
Guess how many people won a Nobel
Marie Curie shares a Nobel in physics with Pierre -
Thompson's model
Thompson would suggest a model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces -
Guess who just won a Nobel
Thompson wins the Nobel in physics -
(NEW DISCOVERY)²
Marie Curie and Pierre Curie discover the radioactive elements polonium and radium -
The Rutherford Atomic Model
Ernest Rutherford created the The Rutherford atomic model. It describes the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative constituents, called electrons, circulate at some distance, much like planets revolving around the Sun. The nucleus was small and dense to account for the scattering of alpha particles. His model serves as his theory and it was a major accomplishment in the scientific world. -
Rutherford's Experiments.
The experiments that led Rutherford to believe this were a series of tests that used a radioactive source to emit alpha particles. The radiation was focused into a narrow beam and then pointed at a thin gold foil and a fluorescent screen. It would produce a burst of light which was visible through a microscope on the back of the screen. The screen was movable which allowed Rutherford to determine whether or not any alpha particles were being deflected by the gold foil. -
Guess who just won a Nobel
Marie Curie becomes the first female to win the Nobel when she wins it in chemistry. She also becomes the only woman in history to win it in two different fields. -
Bohr's model
Proposed the idea of electrons existing at energy levels rather than simply orbiting the nucleus.Bohr thought the model of the atom was incapable of explaining the stability of the atom. He used the Planck constant because he realized a stable atom must have a fundamental constant describing it. With Planck's constant he was able to derive a formula for the quanta of a hydrogen atom. This lead him to the postulate that the electron is quantized. -
Rosalind Franklin is born.
Rosalind Franklin was a British biophysicist and X-ray crystallographer, who was born in 1920 in Britain. -
How did we learn about molecular structure?
Linus Pauling attempted to experiment on the orientation of iron atoms by a magnetic field, through the electrolytic deposition of a layer of iron in a strong magnetic field and the determination of the orientation of the iron crystallises by polishing and etching the deposit, and microscopic examination of the etch figures.
He had in his career over 350 publications. Most of which were findings on molecular structure and the orientation of atoms. These findings opened up more atomic research. -
Guess who just won a Nobel
Bohr wins the Nobel in physics -
A property of matter
During the early 20th century it was believed that light could be described as both a particle and a wave. De Broglie in 1924 introduced the idea that the electron also has this property and so does all of matter. -
wavy and not wavy?
It can be reasoned that the derivation of Schrodinger's wave function is based on De Broglie's hypothesis of matter wave, the law of conservation of energy and the classical plane equation -
The cat can make equations using partial derivatives?
Schrodinger's wave equation .Schrodinger believed that atomic spectra should be determined by an eigenvalue problem. In bohr's theory the electron absorbs and emits fixed wavelengths and jumps within a fixed orbit, this was a good theory for the hydrogen atom. Schrodinger assumed that matter could be described as both wave and particle (he later contested this) he formulated a wave function to describe the energy levels of electrons. -
WOAH! I know my speed and velocity.
Heisenberg proposes the notion of a limit to how precisely position and velocity can be observed simultaneously. This becomes his famous uncertainty principle -
What is a Poincare medal?
De Broglie becomes the first winner of the Poincare med -
NEW DISCOVERY
Chadwick discovered the electron.The electron is a subatomic particle, meaning it has no charge. The discovery of this particle enhanced the knowledge of the atomic structure. By hitting Be atoms with alpha particles, there was a form of radiation emitted. Chadwick examined this and found particles with no charge, the neutron. -
Guess who just won a Nobel
Heisenberg wins Nobel in physics for ¨for the creation of quantum mechanics, the application of which has, inter alia, led to the discovery of the allotropic forms of hydrogen.” -
Guess how many people won a Nobel
Schrodinger shares the Nobel with Dirac. -
NEW DISCOVERY
After hitting a thin piece of aluminium with some alpha rays, a new kind of radiation was discovered. After analyzing the experiment, Irene and Frederic discovered a radioactive isotope of phosphorus. This became the first radioactive element to have ever been created artificially. -
Guess who just won a Nobel
Chadwick wins Nobel prize in physics for the discovery of the neutron -
Guess how many people won a Nobel
Irene Joliot-Curie shares the Nobel in chemistry with her husband for their synthesis of a new radioactive element. -
Precision Balance
The inventors of the precision scale are Albert, Dahlberg, Clayson, and Gordon S. The precision balance contributed to more consistent way to find the mass of an object. And having a standard weight made these measurements accurate and universal, and more study could be done efficiently and accurately. -
Nuclear Fission
Lise Meitner was the first scientist to discover and describe nuclear fission.Nuclear fission is the process in which a large nucleus splits into two smaller nuclei with the release of energy. In other words, fission the process in which a nucleus is divided into two or more fragments, and neutrons and energy are released. This discovery opened the door to further research. -
Molecular structure is described.
Rosalind Franklin's biggest accomplishment was her contribution to understanding fine molecular structures. Her discoveries in this field were unfortunately given no credit because Watson and Crick took credit for most of her work. Her research involving molecular structure helped lead to a much better understanding of the structure of DNA, RNA, viruses, coal, and graphite. Her discoveries and knowledge led to a better understanding of molecules as a whole.
