What oxidation states can nitrogen have?

Nitrogen can have oxidation states of −3, −2, −1, 0, +1, +2, +3, +4, and +5. The most common are −3 (in NH₃ and amines), 0 (in N₂), +2 (in NO), +4 (in NO₂), and +5 (in HNO₃ and N₂O₅). Intermediate states like +1 and +3 appear in N₂O (laughing gas) and HNO₂ (nitrous acid) respectively.

How do you calculate the oxidation state of nitrogen in a compound?

Assign −2 to oxygen, +1 to hydrogen (in most compounds), and −1 to halogens in most cases. Solve for N so the sum equals the total charge of the molecule or ion. For example, in HNO₃: N + 3(−2) + (+1) = 0, so N = +5.

Why does nitrogen have so many oxidation states?

Nitrogen has five valence electrons (2s² 2p³) and an electronegativity of 3.04. It can accept electrons from less electronegative elements like hydrogen (−3 state) or donate electrons to more electronegative oxygen (+1 to +5 states). The half-filled 2p³ configuration is especially stable, contributing to the extreme stability of N₂ (0 state).

What is the oxidation state of nitrogen in ammonia (NH₃)?

In NH₃ each hydrogen is +1 and the molecule is neutral: N + 3(+1) = 0, so N = −3. This is the most reduced state nitrogen achieves, equivalent to formally gaining three electrons from three hydrogen atoms.

What is the oxidation state of nitrogen in HNO₃ (nitric acid)?

In HNO₃: N + 3(−2) + (+1) = 0 → N − 6 + 1 = 0 → N = +5. This is the highest oxidation state nitrogen reaches and gives nitric acid its strong oxidizing properties.

What is the most stable oxidation state of nitrogen?

The 0 state in molecular nitrogen (N₂) is by far the most stable. The N≡N triple bond has a bond dissociation energy of ~945 kJ/mol, one of the strongest in chemistry. Among compounds, −3 (ammonia) and +5 (nitrate) are most stable in aqueous environments at ordinary conditions.

Does nitrogen form a +5 ion like phosphorus?

No. Unlike phosphorus (which forms P⁵⁺ in some ionic contexts), nitrogen never forms a discrete N⁵⁺ ion because its inner d orbitals are unavailable for bonding and the ionization energies are prohibitively high. Nitrogen reaches the formal +5 state only through polar covalent bonds, as in HNO₃ and N₂O₅.

Nitrogen Oxidation States

Name: Nitrogen Oxidation States
Availability: InStock
Author: Nham Vu

Reference tool covering all oxidation states of nitrogen from −3 to +5, with compound examples, electron configuration, and an interactive identifier.

Atomic # 7 N Nitrogen

Atomic Mass

14.007 u

Group

15 (VA)

Period

Block

p-block

Electronegativity

3.04 (Pauling)

Oxidation States

−3, −2, −1, 0, +1, +2, +3, +4, +5

Nitrogen has the ground-state configuration [He] 2s² 2p³, giving it five valence electrons. The half-filled 2p subshell is particularly stable, which explains why N₂ (oxidation state 0) is exceptionally inert. Paired with oxygen's strong electronegativity, nitrogen can be oxidized all the way to +5, while the presence of hydrogen pushes it to −3 — the widest range of any second-period non-metal.

State	Stability	Example	Notes
−3	Very stable (ammonia, amines)	NH₃, NH₄⁺, amines	Most reduced state. Nitrogen gains 3 electrons formally. Basis of all amines, amino acids, and proteins.
−2	Uncommon	N₂H₄ (hydrazine)	Found in hydrazine (H₂N–NH₂) and hydroxylamine derivatives. Both N atoms in N₂H₄ are −2.
−1	Uncommon	NH₂OH (hydroxylamine)	Nitrogen bonded to one OH (oxygen −2, H +1) and two H (+1). Used in organic synthesis and as an antioxidant.
0	Extremely stable (N₂)	N₂	Molecular nitrogen. The N≡N triple bond (~945 kJ/mol) makes this the thermodynamic sink for most nitrogen chemistry.
+1	Metastable	N₂O (laughing gas)	Each N in N₂O is formally +1 (terminal) and −1 (central) — the average is 0; but +1 is the conventional assignment for the compound. Used as an anesthetic and in aerosol cans.
+2	Stable at high T	NO (nitric oxide)	Produced in lightning, combustion, and biologically in blood vessel regulation. Reacts rapidly with O₂ to form NO₂.
+3	Moderate (aqueous acid)	HNO₂, N₂O₃	Nitrous acid is the stable +3 species in water. N₂O₃ is the anhydride. Common intermediate in nitrogen oxide chemistry.
+4	Stable gas	NO₂ (brown gas)	Paramagnetic brown gas from automobile exhaust and smog. Dimerizes to N₂O₄ at low temperature. Key oxidant in acid rain formation.
+5	Stable in acids/salts	HNO₃, N₂O₅, NO₃⁻	Highest oxidation state. Nitric acid and nitrates are the thermodynamic endpoint of nitrogen oxidation. Strong oxidizing agents.

Ionization Energies
IE₁ = 1402.3 kJ/mol | IE₂ = 2856 kJ/mol | IE₃ = 4578 kJ/mol | IE₄ = 7475 kJ/mol | IE₅ = 9445 kJ/mol
Nitrogen never forms a bare N⁵⁺ ion — the +5 state is reached only through polar covalent bonds with oxygen (as in HNO₃). The absence of available d orbitals limits nitrogen's coordination chemistry relative to phosphorus.

Nitrogen's oxidation state varies dramatically across its compounds. The table below covers key inorganic and organic molecules. For molecules with multiple nitrogen atoms, the value shown is per nitrogen atom unless otherwise noted.

Compound	Formula	N State	How to derive it
Ammonia	NH₃	−3	N + 3(+1) = 0 → N = −3
Ammonium ion	NH₄⁺	−3	N + 4(+1) = +1 → N = −3
Hydrazine	N₂H₄	−2	Each N: N + 2(+1) = 0 (ignore N–N) → N = −2
Hydroxylamine	NH₂OH	−1	N + 2(+1) + (−2) + (+1) = 0 → N = −1
Molecular Nitrogen	N₂	0	Elemental nitrogen by convention.
Nitrous Oxide	N₂O	+1	N + N + (−2) = 0; conventional avg = +1 per N
Nitric Oxide	NO	+2	N + (−2) = 0 → N = +2
Nitrous Acid	HNO₂	+3	N + 2(−2) + (+1) = 0 → N = +3
Dinitrogen Trioxide	N₂O₃	+3	Each N: 2N + 3(−2) = 0 → N = +3
Nitrogen Dioxide	NO₂	+4	N + 2(−2) = 0 → N = +4
Dinitrogen Tetroxide	N₂O₄	+4	Each N: 2N + 4(−2) = 0 → N = +4
Nitric Acid	HNO₃	+5	N + 3(−2) + (+1) = 0 → N = +5
Nitrate ion	NO₃⁻	+5	N + 3(−2) = −1 → N = +5
Dinitrogen Pentoxide	N₂O₅	+5	Each N: 2N + 5(−2) = 0 → N = +5
Nitrogen Trifluoride	NF₃	+3	F = −1; N + 3(−1) = 0 → N = +3
Nitrogen Trichloride	NCl₃	0	Cl = −1 (less electroneg. than N is contested); N + 3(−1) = 0 → N = +3 formally, but often treated as 0
Nitrite ion	NO₂⁻	+3	N + 2(−2) = −1 → N = +3
Peroxynitrite	ONOO⁻	+3	Formal charge balance: N = +3 in this reactive intermediate
Urea	(NH₂)₂CO	−3	Each N bonded to 2 H and 1 C(=O): N + 2(+1) − (0) = 0 → N = −3 (C = +4 is the oxidized center)
Aniline	C₆H₅NH₂	−3	NH₂ group: N + 2(+1) = 0 → N = −3 (same as ammonia)

Ground State Configuration

Core (noble gas He)

Valence electrons

Three half-filled p orbitals (Hund's rule)

Notation

Full: 1s² 2s² 2p³

Noble gas: [He] 2s² 2p³

N³⁻ (nitride): 1s² 2s² 2p⁶ (= Ne core)

N⁵⁺ (formal): 1s² (= He core) — only via covalent bonding

Ionization Steps

[He] 2s² 2p³

Neutral atom (7 electrons)

N⁺

[He] 2s² 2p²

Remove one 2p electron — IE₁ 1402.3 kJ/mol

N²⁺

[He] 2s² 2p¹

Remove second 2p electron — IE₂ 2856 kJ/mol

N³⁺

[He] 2s²

Remove third 2p electron — IE₃ 4578 kJ/mol

N⁴⁺

[He] 2s¹

Remove one 2s electron — IE₄ 7475 kJ/mol

N⁵⁺

[He]

Remove last 2s electron — IE₅ 9445 kJ/mol — only through covalent bonds in practice

Why nitrogen's half-filled 2p³ matters
The three singly-occupied 2p orbitals (one per axis: p_x, p_y, p_z) give nitrogen exceptional stability at oxidation state 0. This explains why ~78% of the atmosphere is N₂ and why biological nitrogen fixation requires ~16 ATP per molecule — simply breaking the triple bond to start chemistry costs enormous energy. Once bonded to oxygen or hydrogen, nitrogen is far more reactive and covers eight distinct oxidation states from −3 to +5.

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Summary

Reference tool covering all oxidation states of nitrogen from −3 to +5, with compound examples, electron configuration, and an interactive identifier.

How it works

Select a tab — Oxidation States, Compounds, Electron Config, or Identifier — to explore each topic.
The atom card at the top shows nitrogen's core atomic data: atomic number, mass, group, and electronegativity.
The Oxidation States tab lists every state from −3 to +5 with stability notes and representative compounds.
The Compounds tab shows a searchable table of common nitrogen-containing molecules and their N oxidation state.
The Electron Config tab walks through orbital filling and ionization steps.
The Identifier tab lets you pick a molecule and see its nitrogen oxidation state derived step by step.

Use cases

Students learning oxidation state rules for inorganic and organic chemistry.
Chemistry teachers preparing lessons on nitrogen redox chemistry and the nitrogen cycle.
Anyone studying for A-level, AP Chemistry, or university general chemistry exams.
Researchers checking nitrogen oxidation states in reaction mechanisms or industrial processes.
Engineers working with NOₓ emissions, fertilizers, or nitrogen-containing pharmaceuticals.

Frequently Asked Questions

Last updated: 2026-06-18 · Reviewed by Nham Vu