Electron orbital
From open-encyclopedia.com - the free encyclopedia.
An orbital (also electron orbital) is a mode of behavior of an electron in an atom or molecule.
According to quantum mechanics, an electron in an atom or molecule has two curious properties:
1. An electron's position in space is random, but described by a probability density function <math>\psi^2<math>. (As an object in space, <math>\psi^2<math> is a scalar-valued function of three variables, usually given as spherical coordinates.) In a molecule, <math>\psi^2<math> is very difficult to describe, but in a single atom, it depends upon three so-called quantum numbers: <math>n<math>, <math>l<math>, and <math>m_l<math>. (These numbers appear in equations describing the behavior of the electron.)
2. An electron can only have certain discrete amounts of energy. The particular amount of energy that it has is determined by the probability density function in which it is bound.
The combination of an energy level and a probability density function is called an orbital. The name is intentionally similar to 'orbit'. An orbital determines the energy and possible locations of an electron in much the same way that an orbit determines the energy and possible locations of a celestial body, though the specific mathematical relationships are quite different.
