Electrons move in mysterious ways; the Heisenberg principle states that we can never simultaneously know the location and velocity of such small particles.  But when an electron is bound to an atom within a molecule, it's effectively confined to a particular area, the shape of which is a probability distribution cloud.  At every point within the cloud, there exists a probability that the electron will be located at that point.  This cloud is also known as an orbital.
 
Electrons move in mysterious ways; the Heisenberg principle states that we can never simultaneously know the location and velocity of such small particles.  But when an electron is bound to an atom within a molecule, it's effectively confined to a particular area, the shape of which is a probability distribution cloud.  At every point within the cloud, there exists a probability that the electron will be located at that point.  This cloud is also known as an orbital.
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