We can do the same for the sulfur atom, and we find it has one lone pair of electrons (2 unshared electrons).
Because it penetrates the skin very readily, it is sometimes used as a vehicle for topical application of pharmaceuticals. As 6 - 1 - number of unshared electrons = -1, the number of unshared electrons is 6 or three pairs. Dimethyl sulfoxide is an important polar aprotic solvent that can dissolve both polar and nonpolar compounds and is miscible in a wide range of organic solvents as well as water. An atom of oxygen has six valence electrons (it is group 16) and it has one bond.
The oxygen atom has a formal negative -1 charge. By using the formal charge equation, it is possible to show that the oxygen must have three lone pairs of electrons. We can use the formal charge to determine the number of electrons in the valence shell.įor example, if we look at one of the resonance structures of dimethyl sulfoxide (DMSO, a common solvent). By convention, we always show the formal charge on an atom but not the lone pair of electrons. Drawing ConventionsĪ common question from students is, “ how do I know if carbon has a lone pair of electrons or not?” This can be found from our drawings. A neutral boron atom only has three bonds and six valence electrons. The other element that tricks the unwary is boron.
