What oxidation states does lead exhibit?

Lead most commonly shows +2 (plumbous) and +4 (plumbic) oxidation states. The +2 state is far more stable under ordinary conditions. Lower states (0, −4) are known only in exotic organolead or gas-phase contexts and are not isolable as simple ionic compounds.

Why is Pb²⁺ more stable than Pb⁴⁺?

This is the inert pair effect. Lead's 6s² electrons are stabilised by relativistic contraction of the 6s orbital, making them less available for bonding as atomic number increases. The energy required to involve the 6s pair in forming Pb4+ is not recovered by the compounds formed, so +2 is thermodynamically preferred in most circumstances.

What is lead's electron configuration?

Ground state: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p². When Pb loses two 6p electrons it reaches Pb²⁺: [Xe] 4f¹⁴ 5d¹⁰ 6s². Losing all four valence electrons gives Pb⁴⁺: [Xe] 4f¹⁴ 5d¹⁰.

What is Pb3O4 (red lead)?

Pb3O4, known as red lead or minium, is a mixed-valence oxide containing both Pb²⁺ and Pb⁴⁺ in a 2:1 ratio. Formally it is 2 PbO · PbO2. It was historically used as a red pigment and as a corrosion-inhibiting primer in paints.

Is PbO2 a strong oxidizing agent?

Yes. Lead(IV) oxide (PbO2) is a powerful oxidizing agent because Pb4+ is relatively unstable and readily accepts electrons to revert to the more stable Pb2+ state. This property is exploited in the positive plate of lead-acid batteries, where PbO2 is reduced to PbSO4 during discharge.

How does lead compare to tin in oxidation states?

Tin (the element directly above lead in Group 14) also shows +2 and +4 states, but for tin +4 is the more stable of the two. Lead reverses this preference: +2 is more stable. This reversal is a classic demonstration of the inert pair effect becoming dominant for heavier p-block elements.

Lead Oxidation States

Reference for lead oxidation states: Pb shows +2 and +4, with +2 dominant in most conditions due to the inert pair effect.

Atomic # 82 Pb Lead

Atomic Mass

207.2 u

Group

14 (IVA)

Period

Block

p-block

Electronegativity

2.33 (Pauling)

Oxidation States

+2 (stable), +4

Lead has the ground-state configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p². It can lose the two 6p electrons to reach Pb²⁺ (+2, plumbous), or lose all four valence electrons for Pb⁴⁺ (+4, plumbic). The +2 state dominates in ordinary conditions because of the inert pair effect: relativistic contraction makes the 6s² electrons lower in energy and less chemically available, so removing them costs more energy than the resulting compounds recover.

Oxidation State	Name	Stability	Notes
+2	Plumbous	Most stable	Dominant state in ionic compounds. Pb loses its two 6p electrons, retaining the 6s² pair (inert pair effect). Found in PbO, PbSO₄, PbCl₂, and PbS.
+4	Plumbic	Oxidizing	Less stable; Pb4+ is a strong oxidizer that readily accepts electrons back to reach +2. Found in PbO₂ and PbCl₄ (which decomposes). Key in lead-acid battery chemistry.
0	—	Elemental only	Assigned to pure lead metal by convention. Not a compound oxidation state.
−4 / +3	—	Rare/exotic	−4 seen in organolead anions; +3 in a handful of radical/cluster species. Not relevant to standard chemistry.

Ionization Energies
IE₁ = 715.6 kJ/mol | IE₂ = 1450.5 kJ/mol | IE₃ = 3081.5 kJ/mol | IE₄ = 4083 kJ/mol
The large jump between IE₂ and IE₃ marks the transition from removing 6p to starting on the 6s² inert pair, explaining why +2 is far more accessible than +4 under ordinary conditions.

Lead forms distinct compound families for each oxidation state. Pb²⁺ compounds are the most common and generally more thermally stable. Pb⁴⁺ compounds are strong oxidizers and often decompose on heating. The mixed-oxide Pb₃O₄ contains both states simultaneously.

Compound	Formula	Pb State	Notes
Lead(II) Oxide (Litharge)	PbO	+2	Yellow/red polymorph; used in glass, ceramics, and as a flux. Thermally stable.
Lead(IV) Oxide (Lead Dioxide)	PbO₂	+4	Dark brown solid; strong oxidizing agent. The positive plate active material in lead-acid batteries. Decomposes above 290 °C.
Red Lead (Minium)	Pb₃O₄	+2/+4	Mixed-valence oxide (2 Pb²⁺ + 1 Pb⁴⁺). Bright red pigment historically used in anti-corrosion primers.
Lead(II) Sulfate	PbSO₄	+2	White insoluble solid; forms as the discharge product on both plates of a lead-acid battery.
Lead(II) Sulfide (Galena)	PbS	+2	Principal lead ore; black/gray metallic mineral; historically used as kohl eyeliner.
Lead(II) Chloride	PbCl₂	+2	White solid, sparingly soluble. More soluble in hot water. Used in making ornamental glass (aurene glass).
Lead(IV) Chloride	PbCl₄	+4	Yellow oily liquid; unstable above 0 °C; strong oxidizer. Decomposes to PbCl₂ + Cl₂.
Lead(II) Carbonate (Cerussite)	PbCO₃	+2	White mineral; base of historic white lead pigment. Toxic; largely replaced in modern paints.
Lead(II) Chromate (Crocoite)	PbCrO₄	+2	Bright yellow pigment; also occurs as the mineral crocoite. Used in chrome yellow paints (now largely replaced).
Lead(II) Nitrate	Pb(NO₃)₂	+2	Soluble white salt; oxidizing agent due to the nitrate group; used in fireworks and as a laboratory reagent.

Ground State Configuration

[Xe] core

+50

Noble-gas core (54 electrons through Xe)

+10

Lanthanide contraction core

Relativistic 5d shell

Inert pair — retained in +2 state

Valence — lost on reaching +2 or +4

Notation

Noble gas: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²

Pb²⁺ ion: [Xe] 4f¹⁴ 5d¹⁰ 6s²

Pb⁴⁺ ion: [Xe] 4f¹⁴ 5d¹⁰

Ionization Steps

[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p²

Neutral atom — 4 valence electrons (2 × 6p + 2 × 6s)

Pb⁺

[Xe] … 6s² 6p¹

Remove one 6p electron (IE₁ 715.6 kJ/mol)

Pb²⁺

[Xe] … 6s²

Remove second 6p electron (IE₂ 1450.5 kJ/mol) — stable Pb(II)

Pb³⁺

[Xe] … 6s¹

Begin removing 6s² inert pair (IE₃ 3081.5 kJ/mol) — very unstable

Pb⁴⁺

[Xe] … 5d¹⁰

Remove last 6s electron (IE₄ 4083 kJ/mol) — Pb(IV), strongly oxidizing

The Inert Pair Effect For heavier p-block elements, relativistic stabilisation of the ns² orbital increases with atomic number. In lead, the 6s² pair sits lower in energy than the valence 6p orbitals by a wider margin than in tin above it. This means Pb prefers to shed only the two 6p electrons (giving +2) and retain the 6s² pair — unlike tin, where +4 is the more stable state. Moving from Sn to Pb thus reverses the preferred oxidation state from +4 to +2.

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Summary

Lead (Pb) is a Group 14 p-block metal with atomic number 82. It displays two principal oxidation states — +2 (plumbous) and +4 (plumbic) — with +2 being far more stable in ordinary conditions because of the inert pair effect: the 6s2 electrons become increasingly reluctant to participate in bonding as atomic number rises. This reference covers lead's electron configuration, ionization energies, oxidation state stability, and key compounds including PbO, PbO2, Pb3O4, and PbSO4.

How it works

Click a tab — Oxidation States, Compounds, Electron Config, or Physical Props — to explore each area.
The Oxidation States panel explains why +2 dominates over +4 via the inert pair effect, with a stability table.
The Compounds panel lists common lead compounds with formulas and the oxidation state of Pb in each.
The Electron Config panel shows the orbital filling diagram and ionization energy steps to Pb2+ and Pb4+.
The Physical Props panel provides atomic and material data for quick reference.
Click any monospace table cell to copy its value to your clipboard.

Use cases

Students studying Group 14 trends and the inert pair effect down the group.
Chemistry teachers preparing lessons on post-transition heavy metals.
Environmental scientists referencing lead compound properties for remediation work.
Materials engineers working with lead-acid batteries or lead-based solders.
Anyone preparing for chemistry exams that cover Period 6 or Group 14 elements.

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Last updated: 2026-09-30 · Reviewed by Nham Vu