MODERN ATOMIC THEORY

1. Planck's Quantum Theory of Radiation
In 1900 Planck proposed the quantum theory which states that the energy of an object can only be changed (increased or decreased) by a multiple of a unit of energy called quantum. Planck's law states that a quantum of energy is not fixed, but depends on the frequency of radiation.

E = h . v 

E = quantum energy (joule)

h = Planck constant (6,625 x 10^–34 joule sekon)

v = frequency radiation (sekon^–1)

ν = c / λ 

c = speed of light (3 x 10⁸ m.sekon^–1)

λ = wavelength (m)

Planck's law can be written in the form :  

E = (hc) / λ

2. Bohr Atomic Theory

Bohr's atomic theory dotted starting on the following assumptions.

1. Electrons surrounding the nucleus is at the energy level (trajectory) specific, so the electrons also have a certain energy.
2. Contrary to the theory of Maxwell's electrodynamics, for electrons moving in the trajectory does not emit energy in the form of radiation.
3. Electrons can move from energy level (path) to a low energy level (trajectory) is higher when the electron absorbs energy and vice versa can be moved from the energy levels (path) to a high energy level (trajectory) is lower when the energy release.

 

Figure 1.3 Bohr atom theory 

example:
- Track I have the energy level E1
- Scenic II has the energy level E2
- Track III has the energy level E3 and beyond
The amount of energy absorbed or emitted can be calculated from the following quantum theory.

DE = E2 – E1 = h v =(hc) / λ 

3. Modern Atomic Theory 

Now we will study the development of modern atomic theory based on the concept of wave mechanics. In 1900, Max Planck (1858-1947) suggested that light waves have particle properties, and the transfer of a direct air-electromagnetic radiation in the package or unit of energy called a quantum (asked in the Latin word which means what?). Planck's theory was proven by Albert Einstein (1879-1955) in 1905, who testified that the light waves composed of photons. Then in 1923, Louis de Broglie (1892-1987) explains that a particle, such as electrons, it has wave properties. Based on the concept of wave particle duality, the Erwin Schrodinger (1887-1961) and Werner Heisenberg (1901-1976) in 1926 suggested 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, on a fan (fan) which is being spun seen that the leaves of the fan that fills the entire field. We can not ensure that the location of a piece of fan blade at a given moment, but we can easily make sure where he might be found. Modern atomic theory explains that elektronelektron the atom occupies a space or "cloud" so-called orbital, which is the space where electrons are most likely to be found. Orbital is a certain energy levels in atoms. In 1928, Wolfgang Pauli (1900-1958) suggested that each orbital can accommodate a maximum of two electrons. Electrons move around the nucleus in energy levels or specific skins. To compensate for the repulsive force between them, two electrons in one orbital is always rotated in the opposite direction. Some orbitals combine to form a group called the subshell. Subshell joined to form the skin. One is composed of skin-subshell subshell. Composed of a single subshell orbitals. Accommodate a maximum of two-electron orbital. 

  

My Question

Contrary to the theory of Maxwell's electrodynamics, for electrons moving in the trajectory does not emit energy in the form of radiation. Based on these quotations in the form of electrons emitted? 

4. Atom model of quantum mechanics

Atom model of quantum mechanics developed by Erwin Schrodinger (1926). Before Erwin Schrodinger, an expert from the German Werner Heisenberg developed the theory of quantum mechanics known as the uncertainty principle is "not possible to determined the position and momentum of an object carefully at the same time, which can determined is the probability of finding an electron at a certain distance from the nucleus ".  

Region of space around the core with the probability for electrons called orbitals. Shape and orbital energy levels defined by the Erwin Schrodinger Schrodinger.Erwin solve an equation for the wave function to describe the discovery of a possible limit of the electron in three dimensions. 

Schrodinger equation

x, y and z = Position in three dimensions
Y = Wavefunction
m = mass
ђ = H/2p where h = Plank constant, and p = 3.14
E = Total energy
V = Potential energy

Model of the atom with the orbital path of electrons is called the modern atomic model or atomic model of quantum mechanics is valid until today, as shown in the image below.

Current model of the atom or atomic model wave mechanics

 Shows the electron cloud around the nucleus where the probability of an electron. Orbitals describing the electron energy levels. Orbitals with energy levels of the same or nearly the same will form the sub-skin. Some sub-skin leather combine to form kulit.Dengan thus consists of several sub-skin and consists of several orbital subshell. Although the skin is the same position but not necessarily the same orbital position.

SPECIAL FEATURES MECHANICAL WAVE ATOM MODEL

1. The movement of electrons have wave properties, so the trajectory (orbit) is not stationary like the Bohr model, but following the completion of the square is called the orbital wave function (three-dimensional shape darikebolehjadian greatest discovery of the electron with an atom in certain circumstances).
2.  Orbital shapes and sizes depending on the price of the three numbers kuantumnya. (The electrons occupying the orbital quantum number is expressed in)
3.  Position as far as 0.529 electrons from the core H Armstrong by Bohr instead of something definite, but probable discovery of the electron is the greatest opportunity.

Chadwick trial

 

Weakness Modern Atom Model

Schrodinger wave equation can only be applied exactly to the particle in a box with a single electron and atom