1. Composition: Consists of molecules formed by the chemical bonding of atoms.

2. Formula Representation: Uses the chemical symbols of the constituent elements.

3. Formula Subscripts: Subscripts indicate the relative proportions of different atoms within a molecule. For example, H2O represents a water molecule with two hydrogen atoms and one oxygen atom.

4. Formula Charges: Molecular compounds are generally neutral, meaning they do not have an overall electric charge. Therefore, their formulas do not include charges.

Ionic Compounds:

1. Composition: Consists of positively charged ions (cations) and negatively charged ions (anions) held together by electrostatic forces.

2. Formula Representation: Uses the chemical symbols of the constituent elements and superscript charges to indicate their ionic charges.

3. Formula Subscripts: Subscripts in ionic compound formulas are used to balance the charges of cations and anions to achieve electrical neutrality. For example, NaCl represents sodium chloride, where the +1 charge of Na+ balances the -1 charge of Cl-.

4. Formula Charges: Ionic compounds have an overall neutral charge, so the sum of the charges of the cations must equal the sum of the charges of the anions in the formula.

In summary, the key differences between molecular and ionic compound formulas lie in their composition, representation of charges, and purpose of subscripts. Molecular compound formulas represent neutral molecules, while ionic compound formulas represent electrically neutral combinations of ions.