Naming binary ionic compounds was the first step to being able to name all sorts of ionic compounds.  There is a second set of binary ionic compounds which I usually separate from the beginner ones and these are the ionic compounds that contain transition metals.  These are the metals on the periodic table that can have more than one charge.  

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The important thing to remember with these types of compounds is that you need to have a Roman Numeral which states which charge the metal is in this particular compound.  So Iron(II) is +2, and Iron(III) is +3.  Enjoy this, the Classical system used Ferrous and Ferric, which was more complicated and expected that you had all the charges half memorized.

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Here is a table of the Roman Numerals up to 10, although it is super rare to ever use a number above 4.

Number	Roman Numeral	Number	Roman Numeral
1	I	6	VI
2	II	7	VII
3	III	8	VIII
4	IV	9	IX
5	V	10	X

Now it’s up to you to include the Roman numeral.  Remember that all of the charges of ionic compounds have to zero out.  Add up all your negative charges, and then you know you have to have an equal number of positive charges to cancel them out.  That’s the trick to figuring out what the Roman numeral should be.

Time to introduce polyatomic ions.  These can be sneaky because it makes it look like there are three of four different elements all doing different things when in reality it’s still just two things stuck together.  A cation and an anion.  The polyatomic ion acts just like it is one big thing.  So we treat it like that and balance the same way we did binary ionic.  You’ll probably want a table nearby of common polyatomic ions as well as their charges.

The other thing to remember is that if you are going to have more than one of a polyatomic ion, you need to use parenthesis.  Otherwise you go from something like (NO₃)₂ which is two nitrates to NO₃₂ which is one nitrogen and 32 oxygens.  Yeah… don’t do that.

Ending on a high note.  Naming polyatomic compounds.  No prefixes, nothing special.  As long as you know the name of the cation and the name of the anion you list them in order and you’re finished.  ^_^