-
Period: to
Charles Coulomb
He made pioneering discoveries in electricity and magnetism, and came up with the theory called Coulomb's Law. Coulomb's Law is one of the basic ideas of electricity in physics. The law looks at the forces created between two charged objects. As distance increases, the forces and electric fields decrease. -
Period: to
Antoine Lavoisier
Known as the father of chemistry. He found that mass is conserved in a chemical reaction. The total mass of the products of a chemical reaction is always the same as the total mass of the starting materials consumed in the reaction. His results led to one of the fundamental laws of chemical behavior: the law of conservation of matter, which states that matter is conserved in a chemical reaction. -
Period: to
John Dalton
He discovered that all matter is made up of atoms, which are tiny particles that are essential to making up an element. He also used the Law of Conservation of Mass to determine that every atom is unable to divide itself as well as unable to be destroyed. Dalton also believed that they were spherical particles. -
Period: to
Michael Faraday
Michael Faraday was a British physicist who conducted an experiment where he placed two opposite electrodes in a solution of water containing a dissolved compound. Then discovered that electrical forces were responsible for the joining of atoms in compounds. Which made him develop his two laws of Electrolysis. -
Period: to
J.J. Thomson
In 1897,he discovered the electron by experimenting with a cathode ray, tube. He demonstrated that cathode rays were negatively charged.he also studied positively charged particles in neon gas. he realized that the accepted model of an atom did not account for negatively or positively charged particle, he proposed a model of the atom which he likened to plum pudding. The negative electrons represented the raisins in the pudding and the dough contained the positive charge. -
Period: to
William Crookes
When Crookes was 43, he invented the Crookes Tube in 1875. He discovered the element thallium. The Crookes tube discovered cathode rays and streams of electrons. Crookes invented many instruments to study the behaviors of cathode rays. His studies on cathode rays which have been fundamental in the development of atomic physics. -
Period: to
Antoine Henri Becquerel
Whilst studying the polarization of light within the conduction of an experiment in the year of 1896, he came upon evidence of natural radioactivity nearly by accident when an unexpected reaction occurred in one of his laboratory drawers. Consequently, he received a Nobel Prize in 1903 for his discovery. His discovery contributed to the atomic theory by proving that atoms were not only present, but radioactive atoms were present, as well. -
Period: to
Marie and Pierre Curie
Marie discovered that thorium gives off the same rays as uranium. Pierre was the founding fathers of modern physics. He is known for being a pioneer in radioactive studies.They discovered Radium and Polonium.
“Pierre Curie.” Biography.com, A&E Networks Television, 26 Oct. 2015, www.biography.com/people/pierre-curie-39098.
“Marie and Pierre Curie and the Discovery of Polonium and Radium.” Nobelprize.org, www.nobelprize.org/nobel_prizes/themes/physics/curie/. -
W.K. Roentgen
Roentgen discovered x-rays in 1895. He was studying electrical current through a low pressured gas to learn more on Cathode rays. He found that, if the discharge tube is enclosed in a sealed, thick black carton to exclude all light, the path of the rays became fluorescent. During subsequent experiments he found that objects of different thicknesses interposed in the path of the rays showed variable transparency. Roentgen showed that the rays were shown by the impact of cathode rays on an object. -
Period: to
W.K. Roentgen
Roentgen discovered x-rays in 1895. He was studying electrical current through a low pressured gas to learn more on Cathode rays. He found that, if the discharge tube is enclosed in a sealed, thick black carton to exclude all light, the path of the rays became fluorescent. During subsequent experiments he found that objects of different thicknesses interposed in the path of the rays showed variable transparency. Roentgen showed that the rays were shown by the impact of cathode rays on an object. -
Frederick Soddy
He discovered that radioactive elements experience spontaneous disintegration into isotopes (new elements). He also discovered “half life” (the amount of time it takes for half the atoms of a radioactive substance to decay) and made the calculations on the energy released during this decay. -
Period: to
Max Planck
He was a german theoretical physicist. His works and studies in thermodynamics led the origination of the quantum theory, in which he is best known for. He was awarded with the Nobel Peace Prize for his origination of the Quantum Theory. Many of his works and observations greatly contributed to the understanding of atomic and subatomic processes, as well as how the energy in the universe works. -
Period: to
Paul Villard
He discovered the gamma rays using Ernest Rutherford’s discovery of the alpha rays, positive charges, and the beta rays, negative charges, in 1900. He found that when you eliminate the alpha rays with a lead screen and sweep beta rays with a magnetic field there is still remaining radiation with no charge or penetrating power (gamma rays). -
Enrico Fermi
was mostly known for being the creator of the first nuclear reactor and his role in the creation of the first atomic bomb, but his theory on determining the density of electrons played a large role in the current model of the atom. His theory on how to find the density of electrons allowed for accurate representations of the density of electrons with higher numbers. His theory was one of many progressing theories that led to the model and understanding of the atom that we have today. -
Period: to
Otto Hahn
He is known as the, “father of nuclear chemistry.” He is best known for his discovery of nuclear fission- the process in which a large nucleus splits into two smaller nuclei with the release of energy. He also discovered a new isotope called radiothorium. He would go on to discover a number of other radioactive isotopes and discover radioactive recoil. -
Period: to
Albert Einstein
He came up with a mathematical method of calculating the size of atoms and molecules. His calculations were in good agreement with previous theoretical estimates and were well-received. He came up with the theory of quanta. When quanta of light energy strikes atoms in the metal, the quant force the atoms to release electrons. -
Period: to
Lisa Meitner
She was a physicist, who in 1907 went to Berlin to study with Max Planck. At this time she began to work with Otto Hann. Together they worked together to discover nuclear fission, which would revolutionize the nuclear field. In her research they bombarded atoms with neutrons and noticed a decay of the atom. She determined that the atom was being split into two different elements by this neutron. They called this process "fission". This research led to the nuclear bomb. -
Period: to
Robert Millikan
In 1909, he discovered the charge carried by an electron by using the "oil-drop method." With this, he proved how strong an applied electric field had to be in order to stop the oil drop from falling. He was able to figure the mass of the drop, so he was able to calculate the force of gravity on one drop. -
Ernest Rutherford
Rutherford theorized the nuclear structure of the atom. Experiments done in his laboratory demonstrated that when alpha particles are fired into gas atoms, a few are violently deflected, which means a dense, positively charged central region containing most of the atomic mass. As indicated by Rutherford, practically the whole mass of the atom and at the same time all positive charge of the atom is concentrated in a small space at the center. -
Period: to
Ernest Rutherford
He theorized the nuclear structure of the atom. Experiments done in his laboratory demonstrated that when alpha particles are fired into gas atoms, a few are violently deflected, which means a dense, positively charged central region containing most of the atomic mass. As indicated by Rutherford, practically the whole mass of the atom and at the same time all positive charge of the atom is concentrated in a small space at the center. -
Period: to
Hans Geiger
Hans Geiger co-invented the Geiger Counter.
He began working on the counter in 1907 with Walther Müller and finished in 1911. States that a linear relationship exists between the logarithm of the range of alpha-particles and the radiative time constant, which is involved in the rate of decay of emitting nuclei.
A radiation detector consisting of two electrodes with a low-pressure gas in between.Geiger counters can count radiation but cannot distinguish either the energy or kind of radiation. -
Niels Bohr
He contributed to finding out more about the atomic structure and worked with other scientists to create the quantum theory. He won the 1922 nobel prize from his achievements. He proposed a theory for the hydrogen atom based on quantum theory that energy is only transferred in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits. -
Period: to
Erwin Schrödinger
One of the fathers of quantum mechanics. One of his most well known theories, called “Schrödingers cat”, is an experiment created to apply quantum mechanics to real life. The theory is based on the concept of “superpositions”. Another theory is his work upon others take on quantum theory. The theory was known as the “Schrödinger equation” which formed wave mechanics and revolutionized quantum mechanics. The theory described the changes over time of a physical system in which quantum effects. -
Albert Einstein
He came up with a mathematical method of calculating the size of atoms and molecules. The results from the experiment matched up with previous theoretical estimates and were well-received. He came up with the theory of quanta. When quanta of light energy strikes atoms in the metal, the quant force the atoms to release electrons. -
James Chadwick
In 1932 he made one of the most important discoveries that neutrons do exist. He in this way prepared the way towards the fission of uranium 235 and towards the creation of the atomic bomb. For this amazing discovery he was awarded the Hughes Medal of the Royal Society in 1932. He was elected Fellow of Gonville and Caius College (1921-1935). James was awarded the Nobel Prize in 1935 in physics. He was awarded the nobel prize for his discovery of the neutron. -
Period: to
James Chadwick
In 1932 he made one of the most important discoveries that neutrons do exist. He in this way prepared the way towards the fission of uranium 235 and towards the creation of the atomic bomb. For this amazing discovery he was awarded the Hughes Medal of the Royal Society in 1932. He was elected Fellow of Gonville and Caius College (1921-1935). James was awarded the Nobel Prize in 1935 in physics. He was awarded the nobel prize for his discovery of the neutron. -
Fredric and Irene Curie
This husband and wife team made the discovery that radioactive elements can be artificially produced from stable elements. This was done by exposing aluminum foil to alpha particles. When the radioactive source was removed, the Joliot-Curies discovered that the aluminum had become radioactive. -
Period: to
Fritz Strassmann
In 1938, he identified barium in the residue after bombarding uranium with neutrons, results which demonstrated the previously unknown phenomenon of nuclear fission. In 1945 he was appointed director of the chemistry department at the Max Planck Institute. In he 1966 Received the Enrico Fermi Award along with Otto Hahn and Lise Meitner for their work on nuclear fission. With Otto Hahn, he discovered neutron-induced nuclear fission in uranium (1938) and thereby opened the field of atomic energy. -
Otto Frisch
He and Rudolf Peierls made the Frisch-Peierls Memorandum possible, distributing the idea of producing an atomic explosion. He demonstrated that the fissioning of uranium had the power to be a volatile reaction. When using uranium-235, would be used to create a powerful and dangerous weapon. The effects of these radiations are inconceivable on its greatest after the explosion. An amount of separating the uranium isotopes tops the critical amount of it being explosive. -
Glenn Theodore
Glenn T. Seaborg- Glenn T. Seaborg was a Physicist who discovered a new element with an atomic number of 94. His experiment was started in 1940 when he discovered plutonium. He and a team were also involved in the Manhattan project in which they created a bomb that was made out of plutonium-239. He also developed the actinide transition series in the periodic table and made discoveries of transuranium elements. -
Period: to
Edwin McMillan
In 1940 McMillan and Phillip Abelson produced a new element, element 93, when they bombarded uranium-235 with neutrons. This was the first time a transuranium element had ever been artificially created. McMillan dubbed the new element "neptunium." In 1941, McMillan, Glenn Seaborg, Joseph W. Kennedy, and Arthur Wahl isolated another new element, element 94, for the first time. Following McMillan's practice of naming element 93 after a planet, Seaborg named element 94 "plutonium." -
Period: to
Joseph Kennedy
In 1940, he discovered plutonium. He built the instruments that proved the existence of plutonium. After he helped discover plutonium, he went to Los Alamos to be the head of the chemistry and metallurgy division. There, he was responsible for including purification of plutonium, the fabrication of plutonium and uranium metal, and the handling of polonium and radio-lanthanum. He then received $400,00 from the Atomic Energy Commission. -
Arthur Wahl
Was part of the discovery of plutonium from beta particle emission of
neptunium. -
Philip Abelson
Philip Abelson was an American scientist who’s discoveries which helped obtain the Uranium required for the atomic bomb. In 1940 he developed a liquid thermal diffusion process for uranium-235 isotopes. In 1940 that same year, he discovered the radioactive element neptunium with fellow scientist Edwin McMillan. Nothing they tried could produce as much enriched uraniam as thermal diffusion. The main thing he was responable for creating was the liquid thermal diffusion process for uranium. -
Period: to
Murray Gell-Mann
Murray he started working at the Institute for Nuclear Studies, University of Chicago in 1952, where he introduced the concept of “strangeness”. In 1961, he suggested a scheme for the classification of previously discovered strongly interacting particles into a proper arrangement of families. He thought that it should be on the specific properties known as “quarks”, which later led to the 1964 discovery of the omega-minus particle. He received the Nobel Prize for Physics in 1969. -
Period: to
George Zweig
He discovered many things related to quarks, which make up hadrons (protons and neutrons) and matter in general. He was one of the first to state that hadrons were made up of even smaller substances. He was part of a team led by Murray Gell-Man that fired electrons at protons and recorded how they bounced off. They found "point-like structures" in the protons, and named them "quarks". Because of his team's discoveries, quarks are now a part of the standard model of atomic particles.
