Lead

Lead (Pb) is a post-transition metal with atomic number 82 and an atomic mass of 207.2. Its electron configuration is [Xe] 4f14 5d10 6s2 6p2, which gives it 4 valence electrons.

Lead key data

Symbol	Pb
Atomic number	82
Atomic mass (standard atomic weight)	207.2
Molar mass	207.2 g/mol
Protons	82
Neutrons (most abundant isotope, lead-208)	126
Electrons (neutral atom)	82
Valence electrons	4
Category	Post-transition metal
Period	6
Group	14
Block	p-block
Noble gas notation	[Xe] 4f14 5d10 6s2 6p2
Full electron configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p2
Electrons per shell	2, 8, 18, 32, 18, 4

Atomic mass: IUPAC CIAAW abridged standard atomic weights, 2024. Most abundant isotope: NIST Atomic Weights and Isotopic Compositions.

Measured properties of lead

From PubChem, the US National Institutes of Health. Public domain.

Melting point	600.61 K (327.46 °C), 72nd of 103 by melting point
Boiling point	2022 K (1748.9 °C), 57th of 93 by boiling point
Density	11.34 g/cm³, 22nd of 96 by density
State at room temperature	Solid
Electronegativity	2.33 (Pauling), 14th of 95 by electronegativity
Van der Waals radius	202 pm, joint 57th of 99 by atomic radius
First ionisation energy	7.417 eV (715.6 kJ/mol), 46th of 102 by first ionisation energy
Electron affinity	0.36 eV (34.7 kJ/mol), 48th of 57 by electron affinity
Common oxidation states	+4, +2
Discovered	Ancient

Each rank counts down from the highest value, among the elements PubChem’s table gives one for, and links to that property ranked across the whole table. All of them are collected under periodic trends.

Lead electron configuration

The full electron configuration of lead is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p2. With the noble-gas core collapsed it is [Xe] 4f14 5d10 6s2 6p2, and the outermost subshell is 6p2.

Bohr model of lead (Pb): a nucleus and six shells holding 2, 8, 18, 32, 18 and 4 electrons from the inside out. — Bohr model of lead (Pb). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Orbital box diagram of lead (Pb), [Xe] 4f14 5d10 6s2 6p2, with the xenon core drawn as one bar: one box per orbital, filled by Hund’s rule, showing two unpaired electrons, in 6p. — Orbital diagram of lead (Pb). Image © ScienceQuest, CC BY 4.0: free to reuse with credit to ScienceQuest and a link to this page, as the image licence explains.

Why group and block follow from this is set out in how the periodic table maps electron configuration, and the electron configuration of every element is listed on one page.

Mass of one lead atom

A molar mass is grams per mole, so dividing by the Avogadro constant gives the mass of a single atom, or for an element with more than one natural isotope the average mass of its atoms, and the reciprocal gives how many atoms sit in a gram.

Mass of one atom

one atom = 207.2 / (6.02214076 × 10²³)
= 3.4406 × 10⁻²² g

Atoms in one gram

atoms per gram = 6.02214076 × 10²³ / 207.2
= 2.9064 × 10²¹ atoms

Lead on the periodic table

Lead is in period 6, group 14, in the p-block.

The other elements of group 14 are carbon, silicon, germanium, tin and flerovium.