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460 BCE
Democritus
Democritus is a Greek Philosopher. He lived 460 BC to 370 BC in Abdera, Greece. He lived to be 90 years old in a town on the coast of Thrace near the Nestas River. He was considered the "Father of Modern Science" and the "Laughing Philosopher" because he had a positive attitude outlook on life and loved his job. Also he was known for studying physics, astronomy, zoology, and much more. -
455 BCE
Democritus: Content
He came up with "atomos" which is greek for invisible. Democritus theorized the following: That everything was made up of atoms, atoms are small, indestructible, and unable to be diminished. Atoms differ in size, shape, magnitude, position, and arrangement. Believed atoms and the void are the only things that really exist. Atoms are constant in motion in a void and that collide with each other and can stick together. -
455 BCE
Democritus Continued
In order to discover this revelation he took a seashell and broke it in half and kept breaking it over and over again until he was left with powder and then too a grain of the powder and tried to break it and couldn't. -
Antoine Lavoisier
Antoine Lavoisier is a French Chemist who was born on August 26,1743 and died on May 8, 1794 in Paris France because he was decapitated. He attended law school during his studies and was born into a wealthy family. -
John Dalton
John Dalton was a England chemist, physict, and meterologist. He was born in Manchester, United Kingdom on September 6, 1766 and he died on July 27th, 1844. Dalton started teaching at 12 years old. He and his brother were color blind which struck his motivation to study such. Also when he passed 40,000 people attended his funeral. -
Antoine Lavoisier: Content
His first breakthrough was the study of chemical reactions and made the Law of Conversation of Matter which is the principle that in any closed system subjected to external forces, the mass is constant irrespective of its changes in form. Also the principle that matter cannot be destroyed or created. In the origins of Stoichiometry he declared that water was about 85% oxygen and 15% hydrogen so it holds 5.6 times more oxygen than hydrogen. -
Antoine Lavoisier Continued
Found out that respiration is a form of combustion and that there is no such thing as phlostigon theory. Moreover he helped create an extensive list of new elements including: Oxygen, Nitrogen, Hydrogen, Sulfur, Phosphorus, Carbon, Antimony, Cobalt, Copper, Gold, Iron, Manganese, Molybdenum, Nickel, Platinum, Silver, Tin, Tungsten, and Zinc. (He also considered light an element) -
Antoine Lavoisier Continued
His experiments consisted of the amount of Carbon dioxide and heat given off by a guinea pig as it breathed and compared the results to the quantity of heat produced when they burned carbon to produce the identical amount of carbon dioxide as was exhaled by the guinea pig. -
John Dalton: Content
Dalton's Law states that the total pressure exerted by a mixture of gases is the sum of partial pressure of each individual gas present and that all gases are considered an ideal gas. His Law of Multiple Porportions- explains that when two elements combine to form more than one compound, the mass of the other element, will always be ratios of whole numbers. P
Total
=P
gas 1
+P
gas 2
+P
gas 3
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John Dalton Continued
Soon into his school years Dalton came to the conclusion that he did not like experimenting and made most of his work off the assumption the of previous crediable scientists work. -
John Dalton: Content pt.2
Dalton also inferred that an oxygen atom must weigh 5.6 times more than a hydrogen atom. He made the Amotic Theory which says: 1. All matter is made up of atoms. 2. All atoms of a given element are identical in mass and properties. 3. Compounds are formed by a combination of two or more different kinds of atoms. 4. A chemical reaction is a rearrangement of atoms. -
Max Planck
Was born on April 23rd, 1858 in Kiel, Germany and passed on October 4th, 1947 in Göttingen, Germany. Planck married his second wife two months after his first wife passed, who died of childbirth. Also he was 74 years old when Nazis took over. -
J.J. Thomson
Born on December 18th, 1856 in Manchester, New England and died on August 30th, 1940. He lived in Cambridge, United Kingdom. Thomson married Rose Elizabeth Paget a physics scientist in his lab. He had a son named George and a daughter named Joan. Also he won a Nobel Prize in Chemistry in 1922. -
Marie Curie
Marie Curie was a Polish physicist and Chemist. She was born on November 7, 1867 and passed on July 4, 1934. She lived in Warsaw, Poland. She was considered the First Lady of Science and only is the only person who has ever won a Nobel Prize in Physics and Chemistry. Also 90% of her work was done with her husband. -
Robert Millikan
Robert Millikan was on March 22nd, 1868 and died on December 19, 1953. He lived in San Marino, CA. He was the second american to win the Nobel Prize for physics and coined the term "cosmic rays" . As a child his mother was a dean of a small college. -
Ernest Rutherford
Born on August 30th, 1871 and died on October, 19th, 1937. He lived in England, Canada, and Nelson. Most people thought he was a farmer by the way he dressed. His wife tragically out lived his daughter. He won the Nobel Prize in 1908. -
Albert Einstein
Albert Einstein was a theoretical physicist born March 14th, 1879 in Ulm,Germany and died on April 18, 1955 in Princeton, NJ. Albert was born a Jew. He did not like the violin but he liked to endulge in classical music. Also he renounced his German citizenship to avoid going to war. -
Niels Bhor
He was born October 7th, 1885 in Copenhagen, Denmark and died November 18th, 1962. He won a gold medal from the Royal Danish Academy of Scientists. He also won a Nobel Prize in 1922. -
Erwin Schrodinger
He was born August 12th, 1887 in Vienna, Austria and died January 4, 1961 in Austria.He was awarded the Nobel Prize for physics in 1933 for his work on what is known as Schrodinger equation. He is not as well known as others but he is still relevant in the study of color and colorimetry. He and his wife had no children, but Schrödinger fathered two children by two different women while living in Dublin. -
James Chadwick
James Chadwick was born October 20th, 1891, Bollington, United Kingdom and died July 24, 1974 in Cambridge, United Kingdom.He was knighted in England in 1945 for his achievements in physics. In 1909, he received a Heginbottom scholarship to study physics. Later he sent a detailed account of his results entitled
“The Existence of a Neutron”. When World War I started, he was a prisoner at the Ruhleben Internment camp near Berlin. -
Louis De Broglie
He was born August 15, 1892 in Dieppe, France and died March 19,1987 in Louveciennes, France. He began studying at the age 18 . Also he was awarded the a Nobel Prize in 1929. -
J.J. Thomson: Content
Thomson discovered the electron which was the particle that had a negative charge. With he research he believed the following: Cathode ray particles were at least 1000 times lighter than an hydrogen atom. All cathode ray particles were of identical mass and identical charge. -
Marie Curie: Content
Discovered two new elements Radium and Polonium by grinding pitchblend in a pestle and mortar. She came up with the word radioactivity and with her research she stated the following: Uranium rays conduct electricity and the amount of rays coming from Uranium depends on the amount of Uranium present. -
Max Planck: Content pt. 2
His research conveyed the following: Light releases in unnoticeable groups called "quanta". Light travels in a wave pattern which is called electromagnetic radiation. Light travels in both a medium and a vacuum and is made up of particles called photons which is the quantum theory applied to light. The enery of a photon is a dependent of the wavelength. Lastly, that every electron has it own energy and is pulled around the nucleus. -
Max Planck: Content
Planck studied the electromagnetic spectrum released by a "blackbody" which is an object that releases thermal radiation. He established the Quantum Theory which is theory of matter and energy based on the concept of quantum mechanics. He found that the energy carried electromagneticly must be divisible by a number considers "Planck's Constant". (E=hv) -
Max Planck Continued
He used a quantum experiment consisting of Oscillators and a spectroscope to measure the wavelength. -
Werner Heisenberg
Heisenberg was born December 5th, 1901 in Wurzburg, Germany (which is where he lived) and died February 1st, 1976. He was apart of the Royal Society of London and a member of the American Academy of Sciences. -
Albert Einstein: Content
He became famous for the theory of relativity, which laid the basis for the release of atomic energy. He established law of mass- energy equivalence through his famous formula E=mc². Einstein was able to accurately calculate the average distance an immersed visible particle would travel in a given time. His mathematical laws governing the movements of invisible particles could be tested and measured by observing the motion of the visible. -
Albert Einstein Continued
His experiment consisted of him using a microscope and a stopwatch, and a fluid containing many uniformly sized tiny, yet visible, particles. -
J.J. Thomson: Content pt. 2
In 1907, He discovered the hydrogen atom has one electron. Later on, he made discovery of isotopes because when studying neon he noticed that is existed in two forms with two different masses meaning an element can exist with different masses. Stated that all isotope masses were whole numbers multiples of the hydrogen atom's mass. Moreover, he created a mass spectrometer. -
J.J. Thomson Continued
Thomson used a cathode ray experiment with a cathode of one side and anode on the other with the air pumping outwards to create a vacuum. He allowed his cathode rays to travel through air to see how far they travel before they stopped. Then he deflected the rays with electric and magnetic to the direction they went. Lastly, he used a cloud chamber find out if this was equal to the quantity of a hydrogen atom. -
Robert Millikan: Content
He determined the size of the on a electron which included that it was the smallest charge. His famous experiment was The Oil Experiment. In this experiment he suspended tiny charged droplets of oil between two metal electrodesby balancing downward gravitational force with an upward motion drag and electric forces. -
Niels Bhor: Content
Proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitted. Bohr's theory could explain why atoms emitted light in fixed wavelengths. Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus. -
Niels Bhor: Content pt. 2
Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy. The energy of an electron depends on the size of the orbit and is lower for smaller orbits. The atom will be completely stable in the state with the smallest orbit, since there is no orbit of lower energy into which the electron can jump. -
Ernest Rutherford: Content
Discovered the alpha and beta radiation. He claimed beta particles have greater piercing power than alpha rays, alpha rays a positively charged, aplha particles are helium ions with a 2+ charge. With the help of Fredrick Soddy he concluded: Alpha particles are apart of atomic nature, found that atoms are not indestructible, large atoms that release particles become smaller which means radiactive elements change to other elements when they decay. -
Ernest Rutherford: Content pt. 2
Coined the words beta, alpha, and gamma. Discovered that radioactive elements possess half-lives and made the discovery of nuclear reactions- changed Nitrogen atoms into oxgen atoms by crowding Nitrogen with alpha particles. Discovered the proton and atomic nucleus. Also theorized that protons had to be another subatomic particle that was neutral which would be the neutron. -
Ernest Rutherford Continued
He conducted the Gold Foil Experiment. He shot a beam of alpha particles at a sheet of gold foil and some particles changed directions which bought him to the conclusion that a tiny dense nucleus was the reason for the deflection. -
Louis De Broglie: Content
He contributed and did research on the quantum theory and for predicting the wave nature of electrons. Although there was at first no experimental data to support de Broglie’s theory that electrons behave like waves,in addition to behaving like particles, or quanta, the theory did help explain many previously unaccountable phenomena. For example, experimental evidence had shown that electrons must move around the nucleus of an atom and that certain restrictions are placed on this motion. -
Werner Heisenberg Content
Calculated the behavior of electrons, and subatomic particles that also make up an atom. Instead of focusing mainly on scientific terms, this idea brought mathematics more into understanding the patterns of an atom's electrons. Werner's discovery helped explain the modern view of the atom by going into depth about electrons and how many an atom can hold. -
Werner Heisenberg: Content pt.2
Heisenberg came up with a quantum mechanics that relied only on properties that could be observed. With help from several colleagues, Heisenberg developed a new approach to quantum mechanics. He took quantities such as position and velocity, and found a new way to represent and manipulate them. Max Born identified the strange math in Heisenberg’s method as matrices. -
Erwin Schrodinger: Content pt.2
This model consists of a nucleus surrounded by an electron cloud. Where the cloud is most dense, the probability of finding the electron is greatest, and conversely, the electron is less likely to be in a less thick or dense area of the cloud. This model introduced the idea of sub-energy levels. He is widely known for "Schrodinger's Cat" which basically his experiment but it was considered a thought experiment. -
Erwin Schrodinger: Content
He contributed the Electron Cloud Model. Using math equations to describe the probability of finding an electron in a position. This atomic model is known as the quantum mechanical model of the atom. In contrast to the Bohr model, the quantum mechanical model does not define the exact path of an electron it only predicts the probability of the location of an electron. -
Louis De Broglie: Content pt. 2
His research of the electron as a wave gave an explanation for this restricted motion. In a closed loop the rise and fall of a wave must stretch around the whole loop and have a whole number of wavelengths or it would be cancelled. Which provided proof that an atom has only a certain number of acceptable electron configurations. -
James Chadwick: Content
James discovered the neutron which was a very important discovery. His experiment consisted of him projecting alpha particles toward Beryllium "the light element". The
emitted particles after enduring the Beryllium target which becomes neutrons and fall on the paraffin wax.The paraffin wax in turn releases another type of particle called protons. At that time atoms were thought to be made up of protons
and electrons. -
James Chadwick: Continued
Awhile into his research and calculations Chadwick proved that the particles released from Beryllium were uncharged and had a mass slightly larger than protons. Which is why he decided to call them neutrons.
