1. Planck quantum theory of radiation
In 1900 palnck put quantum theory which states that:
"Energy of an object can only be changed (increased or decreased) by a multiple of the unit of energy called a quantum"
Planck law states that the energy of a quantum is not fixed. But it depends on the frequency of radiation.
E=h.Ѵ
E = quantum energy (Joule)
h = Planck constant (6.625 x 10-34 Joule. sec)
ѵ = frequency radiation (sec-1)
Ѵ = C/ λ
c = speed of light (3 x 108 m.detik-1)
λ = wavelength (m)
Planck law can be written in the form:
E = h.C/ λ
2. Bohr Atomic Theory
Bohr's atomic theory dotted departure on the following assumptions:
a. The electrons in the surrounding nuclei are at the level of energy (trajectory) specific, thus the electron also has a certain energy.
b. Contrary to the theory of Maxwell's Electrodynamics, Selma electrons move in a trajectory does not emit energy in the form of radiation.
c. Electrons can move from the level of energy (trajectory) is low to the level of energy (path) is higher when the electron absorbs energy and vice versa can move from the level of energy (track) the higher the energy level (trajectory) is lower when the energy release.
Much energy is absorbed or emitted can be calculated from quantum theory follows:
ΔE = E2 - E1 = h.ѵ = h.c = h.c.Ѵ
3. Modern Atomic Theory
In 1900, Max Planck (1858-1947) suggested that light waves have particle properties, and the transfer of an electromagnetic radiation takes place in the package or unit of energy called quantum. Planck's theory was proved by Albert Einstein (1879-1955) in 1905, explaining that the light waves composed of photons.
Then in 1924, Louis de Broglie (1892-1987) explains that a particle, for example, proved to have a wave nature of electrons. Based on the concept of this particle duality, Edwin Schrodinger (1887-1961) and Warner Heisenberg (1901-1976) in 1926 suggests that the position or location of an electron in an atom can not be determined exactly. We can only ensure the possibility of the location of the electron. As an analogy, in a fan that is rotating seen that the leaves of the fan that fills the entire field. We can not ascertain the location of a piece of fan leaves it at a certain moment, we can easily tetpai memsatikan where he might be found.
Modern atomic theory explains that the electrons in an atom occupy a space or "cloud" called orbitals, ie the space in which electrons are most likely to be found. Orbital is a certain energy level in atoms. In 1928, Wolfgang Pauli (1900-1958) suggested that each orbital can accommodate a maximum of two electrons. Electrons move around the nucleus at the level of energy or certain skins. To compensate for the repulsive force between them refused, the two electrons in an orbital is always rotating in the opposite direction.
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