Tantalum resists corrosion and forms an oxide that acts as an electrical insulator. This combination enables compact capacitors used in electronic devices. Its alloys also serve demanding mechanical applications. Tantalum often accompanies niobium in ores, requiring careful separation before either element reaches a finished component.
FROM ELEMENT TO APPLICATION
AN ELEMENT IN CONTEXT
How do tantalum metal and its oxide perform opposite electrical roles in one capacitor?
Tantalum capacitor with tantalum oxide dielectric
FOLLOW THIS RELATIONSHIP
Build a conducting structure
Tantalum provides a conducting structure within the capacitor. Its metallic role includes carrying charge to the surfaces involved in storing electrical energy.
Explore the model (optional)
TaFORM → INTERACTION → CONSEQUENCE
Follow the explanation in either direction. These are authored steps, not a physical clock.
Optional: check your understanding
USE THE EXPLANATION
What would undermine the intended dielectric role?
Atomic identity, reference properties and structure models
INTERACTIVE 3D73 visible sites
An electron censusDrag to rotate · scroll or pinch to zoom
[Xe] 4f14 5d3 6s2. 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.
Anders Gustav Ekeberg reported tantalum in 1802, but its similarity to niobium complicated acceptance of their separate identities. Both could occur together, and available chemistry struggled to divide them cleanly. Werner von Bolton prepared pure tantalum in 1903. The century-long story separates recognition, of a chemical near-twin, and preparation of a usable metal, showing why discovery dates should not imply immediate technical readiness.
1802
Tantalum reported
Ekeberg identified the new constituent in mineral material.
Tantalum occurs with niobium in columbite–tantalite and can also be recovered from tin-processing streams. Their shared occurrence makes separation chemistry central to production. The mineral is a complex starting material rather than a natural capacitor component; several conversions create the purified material required for electronics.
Tantalum resists many corrosive environments because of its surface . That oxide also supports an important electronic role as a dielectric in capacitors. Metal conductivity and oxide insulation are complementary here. The useful component depends on controlling the boundary between forms of the same element.
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
3290 K
at standard pressure unless noted
Boiling point in K
5731 K
101.325 kPa
Density in g/cm³
16.69 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
1.5 Pauling
Pauling scale
First ionization energy in kJ/mol
761 kJ/mol
gas-phase neutral atom, ground state
Covalent radius in pm
170 pm
single-bond covalent radius
Common oxidation states
+5
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
2 mg/kg
upper continental crust, mass fraction
Has stable isotopes
Yesderived
Discovery year in CE
1802 CEderived
WHERE IT SITS AMONG ITS NEIGHBORS
Electronegativity across period 6
Ta 1.5 Pauling · Tantalum
Electronegativity across period 6. Exact values.
Cs
0.79
Ba
0.89
La
1.1
Ce
1.12
Pr
1.13
Nd
1.14
Sm
1.17
Eu
1.2
Gd
1.2
Tb
1.1
Dy
1.22
Ho
1.23
Er
1.24
Tm
1.25
Yb
1.1
Lu
1.27
Hf
1.3
Ta
1.5
W
2.36
Re
1.9
Os
2.2
Ir
2.2
Pt
2.28
Au
2.54
Hg
2
Tl
1.62
Pb
2.33
Bi
2.02
Po
2
At
2.2
Electronegativity down group 5
Ta 1.5 Pauling · Tantalum
Electronegativity down group 5. Exact values.
V
1.63
Nb
1.6
Ta
1.5
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.
