Steric Number in VSEPR
Calculating the steric number of a molecule's central atom is a vital step in predicting its geometry by VSEPR theory. On the molecule SF4, for example, the central sulfur atom has four ligands about it, calculated by considering sulfur's coordination number. In addition to the four ligands, sulfur also has one remaining lone pair (expanded octet does not apply in this compound). Thus, the steric number is 5. The central atom's steric number together with the number of lone pairs allows one to predict the geometry of that central atom, using the table of molecular geometries for the VSEPR theory.
Read more about this topic: Steric Number
Famous quotes containing the word number:
“At thirty years a woman asks her lover to give her back the esteem she has forfeited for his sake; she lives only for him, her thoughts are full of his future, he must have a great career, she bids him make it glorious; she can obey, entreat, command, humble herself, or rise in pride; times without number she brings comfort when a young girl can only make moan.”
—Honoré De Balzac (1799–1850)