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Jan 1, 1000
Democritus
-Discovered the 1st Atomic Theory
- Theorized that atoms can hook up with each other and stick together, just like velcro.
-Democritus said that all matter is made up of tiny, indivisible particles called atoms. These atoms were completely solid & in motion.
-Stated that every different type of atom differs slightly. -
John Dalton
-Created Dalton's Law:Explains that the total pressure is equal to the sum of all the pressures of parts, which is for gases.
-Dalton compounded all the work of Lavoisier and Democritus into one, single atomic theory
-Investigated the color blindness condition, known as Daltonism
-Solid Sphere Model
-Recorded/wrote Meteorological observations and essays on weather conditions -
Erwin Schrödinger
-Erwin Schrodinger introduced the Schrodinger Equation
-Allowed the motion of the electron to be determined more accurately & increased the accuracy of Bohr’s model
-Known for showing mathematically that waves can be used to describe electrons in atoms
-Determined the probablility of electrons in atoms -
J.J. Thomson
-Studied cathode rays culminating in the discovery of the electron
-He stated that the atom looks like plum pudding, he invented the plum pudding model
-He determined that all matter is made up of tiny particles that are much smaller than atoms
-Originally he called these particles 'corpuscles,' now called electrons
-Also discovered that neon was composed of 2 different kinds of atoms & proved the existence of isotopes in a stable element -
Robert Millikan
-His earliest major success was the accurate determination of the charge carried by an electron.
-Used the "oil drop experiment" to measure the electron's charge
-His experiment on the photoelectric effect established the wave/particle dual nature of light -
Albert Einstein
-Einstein dealt with classical problems of statistical mechanics, these merged with the Quantum threory
-This led to the explanation of the browian movement of molecules
-He asserted the equivalence of mass and energy, which lead to the famous formula E=mc^2
-Challenged the wave theory of light, suggesting that light could be regarded as a collection of particles.
-Helped lead to Quantum Physics, and won Nobel Prize in 1921. -
Niels Bohr
-One of the main physicists to form the 1st atomic bomb during WWII
-Proposed the idea of "Complementarity"
-He founded the Institute of Theoretical Physics
-Niels Bohr introduced The Quantum Theory
-Said that electrons had quantified amounts of energy
-Proposed a new model of the atom where the electrons travel around the nucleus in orbits determined by their energy levels
-Planetary model -
Louis de Broglie
-Theory of particle-wave duality: Helped explain how atoms, molecules, and protons behave
-1st high-level scientist to call for establishment of a multi-national laboratory -
Werner Heisenberg
-Theory of Quantum Mechanics:Resulted in the discovery of allotropic forms of hydrogen
-Awarded the Nobel Prize for Physics in 1932
-Formulated a new theory in terms of matrix equations
-Later Heisenberg stated his famous Principle of Uncertainty:When measuring 2 related quantities, as position/momentum/energy/time, produces uncertainty in measurement of the other -
Ernest Rutherford
-Discovered that there is something smaller than an atom
-Ernest also discovered that atoms are made of more than one "part", this helped to make different elements
-Assisted in helping Chadwick make a fundamental discovery in the domain of nuclear science
-He proved the existence of neutrons
-Came up with the model of the electron cloud model
-Nuclear Model -
James Chadwick
--Chadwick made a fundamental discovery in the domain of nuclear science
-He proved the existence of neutrons
-Recieved the Nobel Prize in 1935 & was awarded the Hughes Medal of the Royal Society -
Wolfgang Pauli
-Pauli Exclusion Principle:States that no 2 electrons in an atom can be in the same place at the same time
-Zeeman Effect:Splitting of a spectral line associated with a strong magnetic field
-Discovered of the Neutrino:A particle with no charge/mass that carries energy/momentum away from the nucleus of an atom
-Won a Nobel Prize in 1845
