Resources
Learning to Name and Write Formulas:
- Determining the type of compound you are working with.
- Applying the rules for naming or formula writing for that type of compound.
- Practicing until it becomes second nature.
Writing Formulas for Ionic Compounds with Transtion Metals
- Write the symbol and charge for the transition metal. The charge is the Roman Numeral in parentheses.
- Write the symbol and charge for the non-metal. If you have a polyatomic ion, use the list of common polyatomic ions to find the formula and charge.
- See if the charges are balanced (if they are you're done!)
- Add subscripts (if necessary) so the charge for the entire compound is zero.
- Use the crisscross method to check your work.
- Don't write the subscript '1'.
- If you use the criss-cross method and end up with something like Ca2S2 you'll need to reduce the subscripts to Ca1S1 which we write CaS.
In order to write the formula for compounds with transition metal, you must determine the charge on the transition out. We do this by looking at the roman numeral in the name of the compound. That tells us the charge on the transition metal. Once we know the charge on the transition metal we can figure out the subscript on the mon-metal or polyatomic ion.