When it comes to naming ionic compounds,
It’s not as straightforward as with IUPAC Nomenclature.
You have to consider:
- Is it a metal, nonmetal, or a transition/post-transition metal with a varying charge?
- Are there multiple atoms in this ion, like polyatomic ions?
- Is the compound balanced and neutral?
That’s exactly what you’ll learn in this guide to naming ionic compounds, followed by a practice quiz to test your understanding.
And since you’ll have to memorize polyatomic ions (yay!!), I’ve got you covered with the Polyatomic Ions To Memorize Cheat Sheet (below)
Or download my entire Cheat Sheet Collection
Why read if you can watch and listen?
Then skim for the additional tips and practice material below
In this video you’ll learn:
- How to name different types of ions (metal, nonmetal, polyatomic)
- How to balance charges with the Criss-Cross method
- How to draw ionic compounds
- Naming metals with multiple charges (like Fe²⁺ vs Fe³⁺)
- A trick for memorizing polyatomic ion trends
What is an Ion?
An ion is an atom (or molecule) that either gained or lost an electron.
It now has an unequal ratio of protons to electrons, which gives it a charge.
Anions = gained an electron, making them negative
think extra baggage
Cations = lost an electron, making them positive
they're missing baggage
Ionic Compounds Must Be Neutral
Unlike covalent molecules that have a set number of atoms,
ionic compounds are all about ratios.
For example:
CH₄ is always one carbon and four hydrogens.
Not sometimes CH4 and other times C3H12.
But NaCl (table salt) isn't just one sodium and one chlorine
It's a bunch of sodium and chlorine ions,
in a 1:1 ratio.
That ratio keeps the compound neutral.
Balancing Ionic Compounds
If ions are charged,
And ionic compounds are neutral
they have to be perfectly balanced.
Na⁺ cancels out Cl⁻ (
That’s +1 -1 = 0
This also works for ions with higher charges.
Take Ca²⁺ and Cl⁻
Since calcium has a charge of +2,
you’ll need two chloride ions to balance it.
+2 -1 -1 = 0
Or +2 + 2(-1) = 0.
If it gets tricky, use the Criss-Cross Method from the video above
- The charge of your cation becomes the subscript for your anion
- The charge of your anion becomes the subscript for your cation
Naming Ionic Compounds
Now that we know how to balance, let’s get to naming
- Metal Ions: Name as is.
- Nonmetal Ions: Replace the ending with ‘-ide’.
- Transition/Post-Transition Metals: Use Roman numerals if varying charge.
- Polyatomic Ions: You’ll need to memorize their names.
Naming Metal Ions
Metal ions are easy.
Just grab their name from the periodic table:
Na⁺ = Sodium
Mg²⁺ = Magnesium
Naming Nonmetal Ions
Nonmetals require a slight name change.
Drop the ending and add ‘ide’
Br⁻ (Bromine) becomes Bromide
F⁻ (Fluorine) becomes Fluoride
O²⁻ (Oxygen) becomes Oxide
Transition and Post Transition Metals
Transition and Post transition metals (see them on the periodic table)
Are named just as you would metals,
Except….
Because of course they have to make it complicated
Some transition and post transition metals can have more than one charge
- Iron can be Fe²⁺ or Fe³⁺
- Copper can be Cu⁺ or Cu²⁺
- Tin can be Sn²⁺ or Sn⁴⁺
Roman Numerals
When naming these metals, include the charge as a roman numeral in parentheses
Iron(II) Oxide
Tin(IV) Chloride
Traditional Names
Since they couldn’t stop at roman numerals…
Some metals have special names you’ll need to memorize.
As you learned in the video above
Fe²⁺ is Ferrous
Fe³⁺ is Ferric
Confused?
Check out the video for a trick to remember which is ‘-ic’ and which is ‘-ous’ for metals like iron and copper.
Polyatomic Ions
When you thought it couldn’t get any more complicated…
Polyatomic ions are groups of covalently bound atoms that, together, carry a net charge.
Hydroxide (OH⁻) is oxygen and hydrogen combined with a negative charge.
You can find exactly where the charge comes from using my Formal Charge Formula Shortcut
Naming polyatomic ions is simple—just memorize them
- Name
- Formula
- Charge
Polyatomic Ion Cheat Sheet
Click the cheat sheet for the full version,
Or grab my entire cheat sheet collection below
Spend a few minutes doing Active Writing with the Polyatomic Ions to Memorize cheat sheet
And you’ll have them memorized in no time.
You’ll also learn a few tricks from the video
Especially when it comes to remembering the trends of ‘ate’ vs ‘ite’ as you’ll see in
Nitrate vs nitrate
Phosphate vs phosphate
And even the ‘per’ and hypo’ as you’ll see in
Perchlorate, chlorate, chlorite and hypochlorite
Ready to Test Your Knowledge?
Test your Naming Ionic Compounds skills with these questions from the video
Balance, Name and Draw the Following Ionic Compounds:
- Sodium and chlorine
- Calcium and bromine
- Aluminum and oxygen
- Sodium and hydroxide
- Calcium and nitrate
- SnCl₄
Balance and Draw the Following Ionic Compounds
- Magnesium chlorate
- Iron (III) bicarbonate
- Iron (III) oxide
- Lead (II) iodide
Rewatch the video to check your answers and learn from any potential mistakes.
Then,
Try these additional practice questions below
