__standing wave __

a stationary wave as on a strong of a musical instrument; in the wave

__mechanical model __

__the electron in the hydrogen atom is considered to be a standing wave. __

__wave function __

a function of the coordinates of an electron's position in three-

dimensional space that describes the properties of the electron.

orbital - a specific eave function for an electron in an atom. The square of his function gives the probability distribution for the electron.

__quantum (wave) mechanical model __

a model for atoms that surpasses Bohr's quantum model.

__Heisenberg uncertainty principle __

a principle stating that there is a fundamental limitation to how precisely both the position and momentum of a particle can be known at a given time.

__probability distribution__

__ the square of the wave function indicating the probability of finding an electron at a particular point in space__

__radial probability distribution __

the graph of the total probability of finding the electron in each spherical shell is plotted versus the distance from the nucleus.

The quantum mechanical model was constructed by Erwin Schrödinger.

Electrons are defined as standing waves. The electron probability distribution gives the areas in which the probability of electron presence is high. The exact position of the electron is never known as stated by the Heisenberg uncertainty principle:

Δx *Δ(mv) > h/4π

Where Δx is the uncertainty in a particle’s position. Δ(mv) is the uncertainty in a particle’s momentum. It is impossible to know accurately both the position and the momentum of as particle simultaneously. Orbital shapes are defined by probability maps. Orbitals are characterized by the quantum numbers n, l and ml.

The quantum mechanical model is important because it correctly defines the electrons’ movement with relation to the nucleus.

The Bohr model defines the electrons as moving along set orbits around the nucleus. The quantum mechanical model shows that electrons don’t have set orbital but are in random motion confined within the areas of electron probability distribution. The quantum mechanical model works for all elements whereas the Bohr model works only for hydrogen.

The Quantum Mechanical Model vs...

The Bohr Model