Boron shows how changing a material's composition changes its behavior. Boron compounds help make heat-resistant borosilicate glass, while the isotope boron-10 absorbs neutrons and is useful in neutron detection and reactor control. In nature, boron is commonly found in borate minerals.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
How does low thermal expansion help a borosilicate glass object resist temperature changes?
Boron oxide incorporated in borosilicate glass
FOLLOW THIS RELATIONSHIP
Change the glass composition
Boron oxide becomes part of a silicate glass formulation whose composition controls properties, including how much the material expands as its temperature changes.
Explore the model (optional)
BFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Atomic identity, reference properties and structure models
INTERACTIVE 3D5 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[He] 2s2 2p1. Grouping electrons by principal shell connects the neutral-atom configuration to periodic-table patterns.
What this representation means
A three-dimensional counting diagram. Dots are count markers, not measured electron positions; spherical placement and spacing are arbitrary. There are no electron trajectories here. Orbitals describe quantum states.
Boron compounds were used long before the element was isolated. In 1808, Gay-Lussac and Thénard in Paris and Davy in London independently prepared boron-containing material, but their samples were impure. Moissan obtained purer material in 1892, and later purification changed reported properties further. Boron's history distinguishes identifying an element from measuring the properties of a sufficiently pure sample of it.
1808
Independent preparations
French and British researchers prepared impure boron-containing samples.
1892
Improved purification
Henri Moissan obtained a purer form of boron for investigation.
Boron occurs in borate and some spring waters rather than as free elemental deposits. Borax, kernite, and related minerals supply boron compounds for manufacturing. Geological concentration makes selected deposits useful, while the element also appears at much lower concentrations in many natural materials.
Boron forms strongly bonded structures and is a poor electrical conductor at room temperature compared with metals. Its chemistry differs substantially from that of its , borates, or nitride. identity also matters: boron-10 has a neutron-absorption role that cannot be inferred simply from a sample color.
Each section links its supporting references. Descriptions and diagrams were authored for this atlas. Source checks completed. Source checks dated 2026-09-06.
CITE THIS PAGE
Family labels and the group-3 layout are teaching conventions. A table position does not establish an unknown bulk property. Electronic configurations refer to neutral atoms; ions and material environments require their own account.
Read each reference property together with its units, conditions and the reference information below.
Not yet recorded: electron affinity, second ionization energy, ground-state term symbol, van der waals radius, thermal conductivity, specific heat capacity, electrical resistivity, crystal structure, lattice parameter a, space group, abundance in seawater, abundance in the universe, annual production, supply-risk listing, hazard classification, biological role, cas registry number, pubchem cid, wikidata item. These families are declared and awaiting an ingestion run against the source each names; they are listed here rather than shown as empty rows.
Physical
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Phase at 20 °C
solid
293.15 K, 101.325 kPa
Melting point in K
2349 K
at standard pressure unless noted
Boiling point in K
4200 K
101.325 kPa
Density in g/cm³
2.34 g/cm³
solids and liquids at 293 K; gases at 273 K and 101.325 kPa
Atomic and electronic
Intended reference: Pauling electronegativity scale · Widely tabulated; original in The Nature of the Chemical Bond
Electronegativity in Pauling
2.04 Pauling
Pauling scale
First ionization energy in kJ/mol
800.6 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
84 pm
single-bond covalent radius
Common oxidation states
+3
states met in ordinary compounds; not exhaustive
Occurrence and identity
Intended reference: CRC Handbook of Chemistry and Physics · CRC Press
Abundance in the crust in mg/kg
10 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1808 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 2
B 2.04 Pauling · Boron
Electronegativity across period 2. Exact values.
Li
0.98
Be
1.57
B
2.04
C
2.55
N
3.04
O
3.44
F
3.98
Electronegativity down group 13
B 2.04 Pauling · Boron
Electronegativity down group 13. Exact values.
B
2.04
Al
1.61
Ga
1.81
In
1.78
Tl
1.62
The trend uses the same reference-property values as the periodic table. Elements with no recorded value are left out of the line rather than drawn at zero.
