Write the formula for magnesium nitride.
Mg2+ and N3-. Cross the charges: three Mg2+ (total +6) balance two N3- (total -6), giving Mg3N2. This forms as a side product when magnesium burns in air.
What Is the Charge of Nitrogen?
Nitrogen commonly forms N3- N3+ N5+ in introductory ionic compounds.
For ionic-formula work, nitrogen's key charge is -3: the nitride ion N3- in compounds like Mg3N2. In oxyanions the picture flips — nitrogen runs +3 in nitrite (NO2-) and +5 in nitrate (NO3-).
| Element | Nitrogen |
|---|---|
| Symbol | N |
| Atomic number | 7 |
| Common ionic charge | -3, +3, +5 |
| Common ions | N3-, N3+, N5+ |
Visual reference
Nitrogen element image and atomic model
Images are used as visual references; charge rules still depend on the compound.
The electron count behind Nitrogen's charge
Nitrogen's 2s2 2p3 configuration is three electrons short of neon. Facing a metal, it takes those three electrons and becomes nitride. Facing oxygen — the only common element that outpulls it — nitrogen surrenders electron share and shows positive oxidation states up to +5.
The classic Nitrogen error
Confusing nitride (N3-) with nitrite (NO2-) and nitrate (NO3-). One letter changes the species entirely: nitride is a bare nitrogen ion, while nitrite and nitrate are polyatomic ions whose overall charge is -1, not -3.
Worked example: N in a formula problem
N3- and N3+ and N5+ in real compounds
Na3N
sodium nitrogen compound
Sodium ions can balance N3- in simple ionic examples.
CaN2
calcium nitrogen compound
Calcium ions can balance common negative Nitrogen ions.
Questions students ask about nitrogen
What is nitrogen's charge in ammonia?
In NH3 each hydrogen is +1, so nitrogen's oxidation state is -3. In the ammonium ion NH4+ nitrogen is still -3; the extra +1 comes from the fourth proton.
Why is N2 so unreactive if nitrogen wants three electrons?
In N2 both atoms have already satisfied that need by sharing three pairs — a triple bond, the strongest common bond in chemistry (945 kJ/mol). Breaking it is the hard part of making any nitrogen compound.
Which nitrogen oxidation state is in laughing gas?
N2O has nitrogen at +1 on average — one of the odd intermediate states nitrogen passes through between -3 and +5. Nitrogen shows every whole-number state in that range.
How do I use this charge in formulas?
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Where this data comes from
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.