ATOM THEORY OF QUANTUM MECHANICS

Quantum mechanics is the branch of physics that replaces the basic classical mechanics at the atomic and subatomic level. This science provides a mathematical framework for the various branches of physics and chemistry, including atomic physics, molecular physics, computational chemistry, quantum chemistry, particle physics, and nuclear physics. Quantum mechanics is part of quantum field theory and quantum physics in general, which, together with general relativity, is one of the pillars of modern physics. The basis of quantum mechanics is that the energy is not continuous, but discrete - in the form of a 'package' or 'quanta'. The concept is quite revolutionary, as opposed to classical physics assumes that the sustainable energy.

History

In 1900, Max Planck introduced the idea that energy can be divided into several packets, or quanta. This idea is specifically used to describe the intensity distribution of the radiation emitted by the black body. In 1905, Albert Einstein explained the photoelectric effect by concluding that light energy comes in the form of quanta called photons. In 1913, Niels Bohr explained the spectral lines of the hydrogen atom, again by using quantization. In 1924, Louis de Broglie gives his theory of matter waves.

The theories above, though successful, but very fenomenologikal: there is no clear explanation for the quantization. They are known as the old quantum theory.

The phrase "quantum physics" was first used by Johnston in his Planck's Universe in Light of Modern Physics (Natural Planck in light of Modern Physics).

Modern quantum mechanics was born in 1925, when Werner Karl Heisenberg developed the matrix mechanics and Erwin Schrödinger discovered wave mechanics and the Schrödinger equation. Schrödinger several times showed that both approaches together.

Heisenberg uncertainty principle formulated in 1927, and the Copenhagen interpretation formed in almost the same time. In 1927, Paul Dirac combines quantum mechanics with special relativity. He also pioneered the use of operator theory, including notation influential bra-ket. In 1932, Neumann Janos formulate a strong mathematical basis for quantum mechanics as operator theory.

Field of quantum chemistry was opened by Walter Heitler and Fritz London, who publish research covalent bond of the hydrogen molecule in 1927. Quantum chemistry developed by several workers in large numbers, including the American chemist Linus Pauling.

Starting in 1927, the trial began to use quantum mechanics to fields outside of unit particles, which results in quantum field theory. Early workers in this area included Dirac, Wolfgang Pauli, Victor Weisskopf and Jordan Pascaul. This area of ​​research fields developed in the formulation of quantum electrodynamics by Richard Feynman, Freeman Dyson, Julian Schwinger and Tomonaga Shin'Ichiro in the 1940s. Quantum electrodynamics is a quantum theory of electrons, positrons, and the electromagnetic field, and serve as an example for the next quantum theory.

Many worlds interpretation was formulated by Hugh Everett in 1966.

The theory of quantum chromodynamics was formulated in the early 1960s. The theory that we know it today was formulated by Polizter, Gross and Wilzcek in 1975. The initial development by Schwinger, Peter Higgs, Goldstone and others. Sheldon Lee Glashow, Steven Weinberg and Abdus Salam independently showed how the weak nuclear force and quantum electrodynamics could be combined into a single electro-weak force.

Experiments Invention

• Royan double-slit experiment proving the wave nature of light. (Around 2012)

• Henri Becquerel discovered radioactivity (1896)

• Joseph John Thomson - kathoda ray tube experiments (discovers the electron and its negative charge) (1897)

• The study of black body radiation between 1850 and 1900, which can not be explained without quantum concepts.

• Robert Millikan - experiment oil droplets, proving that electric charge occurs in quanta (whole units), (1909)

• Ernest Rutherford - experiment gold leaf plum pudding model of the atom thwart suggesting that the positive charge and atomic mass is spread evenly. (1911)

• Otto Stern and Walter Gerlach conduct the Stern - Gerlach experiment, which shows the quantization properties of the particle spin (1920)

• Clyde L. Cowan and Frederick Reines convincing presence of neutrinos in the neutrino experiment (1955)
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Evidence of Quantum Mechanics

Quantum mechanics is very useful for explaining the behavior of atoms and subatomic particles such as protons, neutrons and electrons that do not obey the laws of classical physics. Atom is usually described as a system in which the electrons (electrically charged negatively) circulate around the atomic nucleus (positively charged). According to quantum mechanics, when an electron moves from the level of higher energy (eg, from n = 2 or shells to-2) to a level lower energy (eg, n = 1 or skin atomic level-1), the energy in the form of a particles of light called photons, are released. The energy released can be formulated as follows:

    E = hf

information:

    E = the energy (J)

    h = is the Planck constant,  (Js), and

    f = is the frequency of light (Hz)

In a mass spectrometer, it has been proven that the spectral lines of atoms in ionization is not continuous, only the frequencies / wavelengths of certain spectral lines can be seen. This is one proof of the theory of quantum mechanics.