Atomic Research Progression



Approx. 460 BC - Approx. 360 BC

Democritus was from Abdera, Greece. He is responsible for "Democritus's atomic theory", this theory stated that atoms make up all matter, they are indestructible, invisible, and homogeneous. Though it is mostly unknown how he found the information in order to create his theory, we do know he did base his work off of Lucretius' studies.

Antoine Lavoisier

1743 - 1794

Antoine was born in Paris to a wealthy family, he discovered that mass happens to conserve itself during a chemical reaction, this led to the discovery of one of the most important laws of chemical behavior. This information was found using very precise measurements to determine the total mass of the products of a reaction, in relation to the reactants. Rather interestingly, he was beheaded during the French Revolution by a Guillotine after being charged with selling tobacco and tax fraud.

John Dalton

1766 - 1844

Born into a Quaker family, in Cumberland England, this man went on to create his own atomic theory. It supported the fact that elements are composed of small particles, atoms. These atoms cannot be created nor destroyed. Though this theory was later found to be not entirely accurate, it did help further the research of other chemists. He based his theory off of the law of constant composition, and the law of conservation of mass. John was colorblind, as was his brother, he researched the topic a lot, so much so that it is sometimes referred to as 'Daltonism'.

J. J. Thomson

1856 - 1940

Thanks to Mr. Thomson, and his experiments with cathode rays, he is responsible for the discovery of the electron. He found this by comparing the heat generated from a ray hitting a thermal junction, and that of a ray which was magnetically deflected. This led to the findings of the rays being 1,000 times lighter than a hydrogen atom, and that their mass was always constant.

Max Planck

1858 - 1947

Planck, born in Kiel, Germany, is known as the 'originator of the quantum theory of energy'. Due to his work in thermodynamics, he made many advances on his theory. He proposed that energy radiates in small amounts, rather than an constant wave. He is responsible for 'Planck's constant', one of the basic constants of physics. Albert Einstein went on to use Planck's constant for his studies of light particles.

Marie Curie

1867 - 1934

Marie Curie, born in 1867 in Warsaw, believed that radiation came from the atom itself, and not from a reaction between multiple molecules. This led to her discovery how to separate radioactive residue from radium. She found most of her discoveries using an electrometer made by her husband and his brother. She contracted aplastic anemia, believed to have come from her long-term exposure to radiation, and died at the age of 67.

Robert Millikan

1868 - 1953

Millikan helped prove that subatomic particles existed, by measuring the charge and mass of an electron. He found this by conducting an 'oil drop' experiment, he observed the electrically charged droplets of oil between multiple metal parallel surfaces. Millikan actually was part of a team that developed meteorological and anti-sub devices during World War II.

Ernest Rutherford

1871 - 1937

He worked with J.J. Thomson regarding the productiveness of x-ray glasses. leading to the discovery of the atom. Though this was impressive, he is better known for his Theory of Atomic Disintegration, this proved that radioactivity involved the disintegration of atoms into different types of atoms. He then made the Rutherford Model of the Atom, which had a little charged nucleus, in the center of electrons. Because of his many contributions, he is known as "the father of nuclear physics".

Albert Einstein

1879 - 1955

This extremely famous scientist was born in Ulm, Germany. He is well-known for many reasons, including his theory of relativity. He also established the law of "mass-energy equivalence", this included the famous formula: E=mc². Throughout his life, he published over 300 scientific works, and won the Nobel Prize in 1921 for his advances in theoretical physics.

Niels Bohr

1885 - 1962

Bohr, originally from Copenhagen, studied under Rutherford, and was one of the first scientist of modern physics. Bohr explained what happens inside of an atom, he did so by combining Rutherford's description of the nucleus, and Planck's theory about quanta. This man dedicated his life toward the peaceful use of atomic physics, he was extremely against the development of atomic weapons for destruction.

Erwin Schrodinger

1887 - 1961

This important scientist was born, and died in Vienna, Austria. He used mathematical equations to describe the positions of electrons. He later developed a model of the atom, known as the quantum mechanical model of the atom. Due to his findings in physics, he was awarded the Nobel Prize in 1933.

James Chadwick

1891 - 1974

Born in Bollington of the United Kingdom, Chadwick went on to publish a paper titled "The Possible Existence of a Neutron". This article proposed that the neutron was an entirely new particle, going against Rutherford's suggestions that the neutron was simply an electron and a proton bound together. Mr. James Chadwich led a rather interesting life, having studied with Hans Geiger in Germany, until he was put in a prison camp when World War II broke out. While in prison, he managed to form a science club and even got permission from the guards for a small lab. Using toothpaste, foil, and wood, he could perform simple experiments.

Louis De Broglie

1892 - 1987

Broglie was born in Dieppe France, and founded the idea of an electron having the properties of a wave, which eliminated restrictions of motion. He was most interested in what he referred to as the "mysteries" of atomic physics, these were the unsolved conceptual problems in atomic physics. He was awarded the Nobel Prize in 1929 for his advances on the wave nature of electrons.

Werner Heisenberg

1901 - 1976

Heisenberg was born in Wurzbug, Germany. He is responsible for the Uncertainty principle, also referred to as the Heisenberg principle. This principle states that the velocity and place of an object will never be able to be measured at the same time. This man was a man of many sciences, having also made notable contributions to hydrodynamics, ferromagnetism, subatomic particles, and cosmic rays. He helped establish the first nuclear reactor, located in Karlsruhe.