• An atomic orbital
  Atomic orbital
  An atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom. This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus...
  
  , describing the behaviour of an electron in an atom
• A molecular orbital
  Molecular orbital
  In chemistry, a molecular orbital is a mathematical function describing the wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region. The term "orbital" was first...
  
  , describing the behaviour of an electron in a molecule

See also

• Electron configuration
  Electron configuration
  In atomic physics and quantum chemistry, electron configuration is the arrangement of electrons of an atom, a molecule, or other physical structure...
  
  , the arrangement of electrons in structures such as atoms or molecules

• Orbital hybridization, a combining of atomic orbitals to form an equal number of hybrid orbitals when forming certain molecule
  Molecule
  A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
  
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