5.14.2010

Bohr Atomic Model

Regardless whether or not capable of Rutherford gave an explanation of Maxwell's rebuttal, but the undeniable fact is the fact that the electrons remain in orbit and fall into the core. Therefore we need a theory to explain this problem.
In 1913 Niels Bohr tried to explain why trajectories of electrons do not fall into the core. Bohr advantage of the fact that the spectrum of light generated by an atom. Facts show that the atomic spectrum of light energy emitted by the atom only at certain frequencies, so it can be ascertained electron in an atom must have an energy only at certain prices, or quantized, and unlikely to have any energy at a price that lies between the prices that particular. For this reason, Bohr made the statement that atoms have energy levels at certain prices. Bohr picture of atomic model is like a ball with the nucleus located in the middle. Leather ball as the trajectory of electrons is called the orbit or skin of a cross. Each cross the skin from the inside out given nomor1, 2, 3. Numbers that show the skin of this cross with a notation called quantum number n which is correlated with the level of energy. Bohr also said if an electron with a certain energy is at a cross skin with an appropriate energy level (called stationary) then the electron will not emit or absorb energy, but if the electrons are in energy levels that do not fit then he will release or absorb energy to be at the appropriate level. Based on a series of reasoning, Bohr makes the atom which is an improved model of the atomic model of Rutherford.
1) Atom is the little things that are hollow, with the core being the middle. The core is massive, positively charged atoms and the mass concentrated in it. Outside the core at a relatively far distance the electrons have a negatively charged and orbit around the nucleus with a very high speed like planets around the sun in our solar system.
2) Outside the core there are energy levels with specific prices. This energy level is also called cross-electron skin. Skin cross closest to the core is numbered 1, the next two, three, four,. . . . . n. This number is called quantum numbers. Skin cross with:
n = 1 is called the K leather
n = 2 is called the L skin
n = 3 is called the skin M
n = 4 called skins N
n = 5 is called the skin O
n = 6 is called the skin P
n = 7 is called skin Q
3) Electron trajectories that remain outstanding in accordance with the energy of which (called ideal if the electron energy equal to the amount of occupied energy level). Electrons that are on the path itself is the path that match the energy level is called stationary. In the circulation stationary electron does not emit or absorb energy.
4) If the stationary electrons absorb a certain amount of energy, electrons will move to the track with a greater level of energy and this state is called excited states. This excited state is temporary, and eventually the electron will return to the track stationary while releasing energy in the form of the spectrum.
5) Because the electron trajectory is a curved path, the electrons generate physical quantity called angular momentum. The amount of angular momentum is n, where h = Planck's constant
6) Each leather cross, at most can only contain electrons as 2N2.
So:
K skin contains a second maximum. 12 = 2 electrons
maximum L contains two skin. 22 = 8 electrons
AD skin contains a second maximum. 32 = 18 electrons
and so on.

Bohr Atomic Model Weaknesses
While it seems to have been very imperfect, it turns out Bohr atom model, which is also called the Rutherford-Bohr model still has several weaknesses, among other things:
1) Bohr atom model and all calculations can be used not only to explain the hydrogen spectrum, but not able to explain the phenomenon of spectrum from other atoms.
2) His statement that states the amount of angular momentum of electrons is nh / 2  turns out is also wrong. Later will be proved in the atomic model of wave mechanics that the electron angular momentum never nh / 2 .
3) Bohr was not able to explain where it comes from quantum number n.