Formula Mass for Ionic Compounds
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
An ionic compound's formula mass sums the average atomic masses of every ion shown in its formula unit, cation and anion together.
Show
Sodium chloride's formula mass adds sodium's average mass to chlorine's, since NaCl's formula unit contains exactly one of each ion.
Watch for
Ionic compounds form no discrete molecules, so their formula mass is never correctly called a molecular mass.