Astatine Electron Configuration,
Atomic Structure & SPDF Orbitals
Complete multi-model analysis of Astatine (At). Explore its [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵ electron configuration, atomic structure, and how its 7 valence electrons drive its exact chemical properties.
Fact-Checked Scientific Data
Electron configurations and valence mechanics verified against PubChem API & IUPAC standards.
What is the Electron Configuration of Astatine?
Snippet: To fundamentally understand Astatine, you must examine its electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁵. Being a p-block halogen, this chemical element relies on its shorthand valence arrangement ([Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵) to form high-strength bonds. With precisely 85 electrons orbiting the atomic nucleus, Astatine sits comfortably in period 6, group 17.
Astatine Bohr Model Explained
The Bohr model of Astatine provides a clear, 2D planetary visualization of its 85 electrons dynamically orbiting the central nucleus. By stacking its electrons outward into 6 distinct rings—filling in the specific pattern of 2, 8, 18, 32, 18, 7—the Bohr diagram fundamentally exposes why Astatine has 7 valence electrons available for reactivity.
While the interactive Bohr visualizer above demonstrates the dynamic movement, fundamentally the Bohr model maps Astatine's structure in concentric rings. It gives an immediate intuitive grasp of why Astatine possesses 7 valence electrons without needing complex wave mechanics.
SPDF Orbital Model of Astatine
The SPDF quantum orbital model explains Astatine's true three-dimensional structure. Dictated by the Aufbau principle, Astatine's 85 electrons populate spherical (s), dumbbell (p), clover (d), or complex (f) probability clouds in a strict energy sequence: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁵. It terminates precisely in the p-block.
s
Spherical, max 2e⁻
p
Lobed, max 6e⁻
d
Cloverleaf, max 10e⁻
f
Complex, max 14e⁻
The SPDF structure determines far more than just location; it defines Astatine's magnetic footprint, its ionization energy curves, and precisely how it physically overlaps with neighboring atoms to form complex covalent or ionic bonds. Our interactive SPDF diagram above allows you to see this subshell hierarchy mathematically stacked from lowest to highest energy states.
Electron Configuration Breakdown
- Full Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁵
- Noble Gas Shorthand: [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
- Total Shells: 6 shells containing (2, 8, 18, 32, 18, 7) electrons respectively.
- Terminal Block: The final electron lands in the p-block, characterizing it as a halogen.
Valence Electrons in Astatine
Valence Electrons
7 Valence Electrons
Astatine tends to gain electrons to achieve a stable octet, driving its chemical reactivity.
Given that Astatine possesses exactly 7 valence electrons in its absolute outermost shell, it is heavily inclined to accept or share electrons to complete its octet as an electronegative anion.
Astatine Atomic Structure Table
Why Astatine Behaves This Way
The rarest naturally occurring element on Earth — at any given time only around 28 grams (~1 oz) exists in the entire planet's crust. All isotopes are radioactive with short half-lives. Astatine-211 is a highly promising targeted alpha therapy (TAT) agent for cancer, as alpha particles are lethal to cancer cells while sparing surrounding tissue.
Real-World Industrial & Biological Context
Comparison with Neighbour Elements
When measured against its immediate periodic neighbours, Astatine demonstrates a calculated structural momentum. Its atomic radius (150 pm) and electronegativity (2.2) represent a critical transition point across Period 6.
Astatine Orbital Build Challenge
Click orbitals in Aufbau order to build the correct electron configuration. Earn 100 XP per correct answer.
Orbital Build Challenge
Construct the complete SPDF electron configuration for Astatine (85 electrons) in correct Aufbau order. Click orbitals in sequence.
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Frequently Asked Questions about Astatine
What is the exact electron configuration of Astatine?
The complete, full-length electron configuration of Astatine is written universally as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 5s² 5p⁶ 4f¹⁴ 5d¹⁰ 6s² 6p⁵. Using standard noble-gas core condensation, its shorthand notation is abbreviated to [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵.
How many valence electrons does Astatine contain?
Based on its position in group 17 of the periodic table, Astatine possesses exactly 7 valence electrons in its absolute outermost shell. These specific electrons are strictly responsible for dictating its chemical reactivity, bonding geometry, and physical phase.
What is the Bohr shell distribution for Astatine?
The classical Bohr model of Astatine illustrates its 85 electrons distributed sequentially across 6 major energy shells. The exact electron count per shell, from the innermost ring stretching outward, is: 2, 8, 18, 32, 18, 7.
What are the physical and chemical properties of Astatine?
Astatine is a halogen with a measured atomic mass of 210.000 u. It has an atomic radius of 150 pm and an electronegativity rating of 2.2. It typically exhibits oxidation states involving 7, 5, 3, 1, -1.
Why is Astatine placed in the p-block of the periodic table?
Astatine is classified strictly as a p-block element because its absolute highest-energy (terminating) electron physically resides within an p-subshell according to the quantum mechanical Aufbau filling principle.
How many total protons, neutrons, and electrons are inside a neutral Astatine atom?
A perfectly neutral atom of Astatine contains exactly 85 protons in its dense nucleus and 85 electrons orbiting it. While the neutron count varies dynamically by isotopic mass, its most abundant, naturally occurring isotope possesses approximately 125 neutrons.
Is Astatine chemically reactive or stable?
Operating with 7 valence electrons, Astatine's reactivity is determined by its drive to achieve a noble-gas octet. Because its outer shell is incomplete, it is chemically reactive and violently seeks to form bonds with other elements.
What are the most common real-world uses of Astatine?
Due to its specific atomic structure and electron mechanics, Astatine is heavily utilized in At-211 Targeted Alpha Cancer Therapy, Research Only, Radioactive Tracer Studies. Its macroscopic industrial properties are a direct physical manifestation of its microscopic electron configuration.
Does Astatine follow the standard Aufbau principle rules?
Yes. Astatine systematically and predictably follows the standard Madelung Aufbau energy-filling rules without any abnormal electron migrations.
What is the symbol and atomic number of Astatine?
The internationally recognized chemical symbol for Astatine is At, uniquely identifying it alongside its absolute atomic number of 85 across all global chemical databases like IUPAC and PubChem.
Electronic Configuration of All 118 Elements
Element Dictionary — All 118 Elements
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