Quantum mechanics model of the atom People

Albert Einstein

Albert Einstein was a German physicist who developed the theory of relativity, which states that time, space, and mass are relative to each other and not fixed. He theorized that E=mc^2, which means that energy and mass are related. In 1905 he created the Quantum Theory of Light which states that light comes in tiny particles called photons. He made this discovery based on the work of Max Planck. He also printed two papers that, in essence, proved the existence of atoms.

Dmitri Mendeleev

Dimitri Mendeleev was the Russian chemist who developed a periodic table of the chemical elements and predicted the discovery of several new elements. He arranged the elements according to their mass (which is not exactly how it is today, though it is close). The first periodic table was organized by increasing atomic mass, vertically, and separated by similar properties.

Erwin Shrodinger

Erwin Schrodinger used de Broglie's hypothesis and Bohr's idea (that energy can be quantized) and created a mathematical treatment of the electron called the Quantum Theory. This work led to Electron Cloud Model. This is the current atomic model.

F. H. Hund

F. H. Hund was a German physicist was came up with Hund's Cases and Hund's Rule(s). Hund's rule of maximum multiplicity is a rule based on observation of atomic spectra, which is used to predict the ground state of an atom or molecule with one or more open electronic shells. The rule states that for a given electron configuration, the lowest energy term is the one with the greatest value of spin multiplicity.

Louis de Broglie

Louis de Broglie was a French physicist. He developed the wave mechanics theory of electrons. He discovered Duality of Matter by taking a beam of electrons (matter) and getting the beam to end like a light wave. He use the wavelength = h/mv to demonstrate the wave characteristics of electrons and other moving masses.

Max Planck

Max Planck was the German physicist whose explanation of blackbody radiation in the context of quantized energy emissions initiated quantum theory (1858-1947). He proved that subatomic energy was emitted from particles called them "quanta." This called into question the distinction between matter and energy. He also created what is now known as Planck's Constant. It relates the energy in one quantum (photon) of electromagnetic radiation to the frequency of that radiation. In the International System of units (SI), the constant is equal to approximately 6.626176 x 10-34 joule-seconds.

Samuel Goudsmit and George Uhlenbeck

These two Dutch-American scientists created the idea of "electron spin." This means that there is an inherent angular momentum for electrons. s = 1/2

Werner Heisenberg

Werner Heisenberg was a German physicist who created the "principle of uncertainty". The theory said that because it is impossible to know the speed and position of an electron, it is not possible to predict its behavior. Therefore, there is only tendency and probability. He received a Nobel Prize for the "creation of quantum mechanics."

Wolfgang Pauli

Wolfgang Pauli formulated the Pauli exclusion principle which stated that no two electrons could exist in the same quantum state, identified by four quantum numbers including his new two-valued degree of freedom. The idea of spin originated with Ralph Kronig. George Uhlenbeck and Samuel Goudsmit one year later identified Pauli's new degree of freedom as electron spin. He also added a fourth quantum degree of freedom. He also predicted the neutrino, an essentially neutral particle that is very light and moves quickly.

Niels Bohr

Niels Bohr was a Danish physicist who worked with Rutherford and proposed that electrons surround the nucleus in specific energy levels or shells (it could be "quantized"). Because of this, each electron must have a particular amount of energy. He also confirmed Broglie's hypothesis about the duality of matter. His philosophical principle of complementarity stated that items could have apparently mutually exclusive properties, such as being a wave or a stream of particles, depending on the experimental framework.