The formula unit for an ionic compound is similar to an empirical formula in that both give the simplest whole-number ratio of atoms of each element in a compound.
Emperical formula give the smallest whole number ratio of atoms in a compound
FeS
Xn+Yn-
Calcium Bromide
Aluminum and lithium are both metals and will not form any ionic compounds together.
What you write for an ionic compound is called the formula unit, but the formula unit is almost always the same as the empirical formula. The answer to your question could not be the molecular formula because an ionic compound is not a molecule.
NaF is the empirical formula
an empirical formula For an ionic compound, the empirical formula is called a formula unit.
MgO is an ionic compound and all the ionic compounds are represented by their emperical formula because actual no of atoms can not be represented due to a very huge crystal formation.(crystal lattice).
The concept of empirical formulas apply to ionic compounds. You write the action first, the anion second, and use the minimal amount of atoms possible to make a neutral compound. A molecular formula would be the formula without necessarily the minimum amount of atoms.
Formula: K3N
Silver oxide is an ionic compound so its molecular and empirical formula is same Ag2O
Emperical formula give the smallest whole number ratio of atoms in a compound
FeS
Xn+Yn-
Calcium Bromide
formula mass can be used for ionic compounds.