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Stated the Law of Definite Proportions which said that the ratio of elements in a compound are always the same / constant. Believed that matter could be put together in certain patterns to make bigger, different, unique matter.
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Proposed that all matter is made of atoms and atoms are indivisible and indestructible. All atoms of a given element are identical in mass and properties.
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Believed that electrons can act like both particles and waves, just like light. Waves produced by electrons contained in the orbit around the nucleus set up a standing wave of a certain energy, frequency, and wavelength.
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Studied the effect of electricity on solutions and coined the term "electrolysis" as a splitting of molecules with electricity, developed laws of electrolysis.
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Discovered one type of radioactivity beta particles which is due to high speed electrons leaving the nucleus of the atom.
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Postulated the nuclear structure of the atom. His model described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, called electrons, circulate at some distance.
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Discovered protactinium. Collaborated with Meitner and Fritz Strassman on the process if irradiating uranium and thorium with neutrons.
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Bohr model shows the atom as a small, positively charged nucleus surrounded by orbiting electrons. He was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element.
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Studied uranium and thorium and called their spontaneous decay process "radioactivity". She and her husband Pierre discovered the radioactive elements polonium and radium.
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Used the idea of quanta (discrete units of energy) to explain hot glowing matter.
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He suggested the model of the atom as a sphere of positive matter in which electrons are positioned by electrostatic forces.
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Published e=mc2.
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He and his colleagues are responsible for the identification of more than 100 isotopes of elements throughout the periodic table. He discovered plutonium.
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He attempted to measure the charge of an electron. To do this, he used the oil drop experiment,
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Viewed electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom.
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He discovered the neutron. Predicted the atom would have a neutron. Established that the atomic number is determined by the number of protons in an atom.
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Heavy elements capture neutrons and from unstable products which undergo fission. This process ejects more neutrons continuing the fission chain reaction.
