What is the electron configuration of tantalum?

Tantalum (Ta, Z=73) has the ground-state electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d³ 6s². The 73 electrons are distributed across 19 subshells spanning six principal shells.

What is the noble-gas shorthand for tantalum?

The condensed (noble-gas) notation is [Xe] 4f¹⁴ 5d³ 6s², where [Xe] represents the filled 54-electron xenon core.

How many valence electrons does tantalum have?

Tantalum has 5 valence electrons: 3 in the 5d subshell and 2 in the 6s subshell. These are responsible for its +5 maximum oxidation state.

Why does tantalum have a +5 oxidation state?

Tantalum can lose all five valence electrons (5d³ and 6s²) to reach the stable [Xe] 4f¹⁴ noble-gas-like core, giving Ta⁵⁺. The +5 state is common in oxides and halides such as Ta₂O₅.

What block and period is tantalum in?

Tantalum is in Period 6, Group 5 (VB), and belongs to the d-block of the periodic table. It is a transition metal.

Why does the 4f subshell fill before the 5d in tantalum?

After lanthanum (Z=57), the 4f subshell lies slightly lower in energy than 5d. So electrons fill 4f completely (14 electrons, Z=58–71, the lanthanide series) before re-entering the 5d subshell for Group 4–12 metals in Period 6 such as tantalum.

What is tantalum used for?

Tantalum is used in high-performance capacitors for electronics, surgical implants and bone repair (biocompatible), superalloys for jet engines, and chemical process equipment due to its exceptional corrosion resistance.

Tantalum Electron Configuration

Name: Tantalum Electron Configuration
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Author: Nham Vu

Interactive reference for tantalum's electron configuration ([Xe] 4f¹⁴ 5d³ 6s²), orbital diagram, quantum numbers, and key atomic properties.

Z = 73 Ta Tantalum

Tantalum — Electron Configuration

Atomic number 73 · Transition metal · Period 6, Group 5 · d-block

[Xe] 4f¹⁴ 5d³ 6s² 73 electrons 5 valence e⁻ +5 max oxidation

Subshell Breakdown

Subshell	Type	Electrons	Max Capacity	Notation
1s	s orbital, shell n=1	2	2	1s²
2s	s orbital, shell n=2	2	2	2s²
2p	p orbitals, shell n=2	6	6	2p⁶
3s	s orbital, shell n=3	2	2	3s²
3p	p orbitals, shell n=3	6	6	3p⁶
3d	d orbitals, shell n=3	10	10	3d¹⁰
4s	s orbital, shell n=4	2	2	4s²
4p	p orbitals, shell n=4	6	6	4p⁶
4d	d orbitals, shell n=4	10	10	4d¹⁰
4f	f orbitals, shell n=4	14	14	4f¹⁴
5s	s orbital, shell n=5	2	2	5s²
5p	p orbitals, shell n=5	6	6	5p⁶
5d valence	d orbitals, shell n=5 (valence)	3	10	5d³
6s valence	s orbital, shell n=6 (valence)	2	2	6s²
Total		73

Full Configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d³ 6s²

All 19 subshells written explicitly.

Noble-Gas Shorthand

[Xe] 4f¹⁴ 5d³ 6s²

[Xe] = the filled 54-electron xenon core.

Shell Fill Summary

Shell 1 (n=1) — 1s² 2 / 2 electrons (100%)

Shell 2 (n=2) — 2s² 2p⁶ 8 / 8 electrons (100%)

Shell 3 (n=3) — 3s² 3p⁶ 3d¹⁰ 18 / 18 electrons (100%)

Shell 4 (n=4) — 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 32 / 32 electrons (100%)

Shell 5 (n=5) — 5s² 5p⁶ 5d³ 11 / 50 electrons (22%)

Shell 6 (n=6) — 6s² 2 / 72 electrons (3%)

Shell 5 can hold up to 50 electrons (5s + 5p + 5d + 5f + 5g). Tantalum uses only 11 of those slots. Shell 6 can hold up to 72 but tantalum uses only 2.

Orbital Box Diagram (valence region)

The xenon core (1s² … 5p⁶, 54 electrons) is shown collapsed. The valence subshells 4f, 5d, and 6s are expanded.

[Xe]

Core — 54 electrons fully paired (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶)

14 electrons across 7 orbitals — fully filled

empty

3 electrons — each in its own orbital (Hund's rule), 2 empty — valence

2 electrons (paired) — valence

Each box is one orbital. Opposing arrows denote paired electrons (+½ and −½). The three 5d electrons each occupy a separate orbital before pairing (Hund's rule). Highlighted borders mark valence subshells (5d and 6s).

Quantum Numbers — Valence Electrons (5d³ 6s²)

Electron #	n	l	mₗ	mₛ	Subshell
69	5	2	-2	+½	5d
70	5	2	-1	+½	5d
71	5	2	0	+½	5d
72	6	0	0	+½	6s
73	6	0	0	−½	6s

n = principal; l = azimuthal (l=2 → d, l=0 → s); mₗ = magnetic; mₛ = spin. Electrons 1–68 fill the [Xe] core and 4f subshell.

Summary

Interactive reference for tantalum's electron configuration ([Xe] 4f¹⁴ 5d³ 6s²), orbital diagram, quantum numbers, and key atomic properties.

How it works

The Aufbau principle fills orbitals from lowest to highest energy.
After filling the xenon core (54 electrons), electrons enter the 4f, 5d, and 6s subshells.
All 14 electrons of the 4f subshell are filled before any 5d electrons enter.
Tantalum's three 5d electrons occupy separate orbitals with parallel spins (Hund's rule) before any pairing.
Noble-gas notation abbreviates the 54-electron xenon core as [Xe], leaving [Xe] 4f¹⁴ 5d³ 6s².
The interactive tabs let you explore the configuration, orbital diagram, and element data separately.

Use cases

Quick reference for chemistry homework or exam review on d-block transition metals.
Visualize 4f subshell filling through the lanthanide series before the 5d block.
Understand why tantalum commonly exhibits +5 and +4 oxidation states.
Compare tantalum to its Group 5 congeners vanadium and niobium.
Study how relativistic effects in Period 6 influence electron configuration and chemistry.
Teaching aid for atomic structure, periodic trends, and f-block insertion.
Verify quantum numbers for tantalum's outermost valence electrons.

Frequently Asked Questions

Last updated: 2026-07-25 · Reviewed by Nham Vu