プロトアクチニウム

Also known as Pa, element 91, 91Pa, protoactinium, brevium

原子番号91の元素

OverviewAI-generated

Protactinium is a chemical element with the symbol Pa and atomic number 91. Its standard chemical formula is Pa. The element has a mass of 231.03588. It was discovered in 1917.

The element has an electronegativity of 2 and an ionic radius of 1.04. Its canonical SMILES representation is [Pa]. The Unicode character for the element is 鏷. In its neutral state, it has a charge of 0. It has zero hydrogen bond donors and zero hydrogen bond acceptors. The topological polar surface area is 0.

The element is referenced in 138 PubMed articles. It is cited by 717 other encyclopedia articles.

Synthesized by Vinony from 23 facts across 4 sources: Wikidata, PubChem, PubMed, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.

Chemical data

Formula: Pa
Molecular weight: 231.03588 g/mol
IUPAC name: protactinium
SMILES: [Pa]
InChIKey: XLROVYAPLOFLNU-UHFFFAOYSA-N
Polar surface area: 0 Å²
H-bond donors: 0
H-bond acceptors: 0
Formal charge: 0

via PubChem

Research

138 papers

How novel is protactinium: Insights into the structure and properties of (PaO)(2)(SO(4))(3)(H(2)O)(2).Science advances · 2025Gogolski JM, Gotthelf G, Hoover ME et al.DOI: 10.1126/sciadv.adt7782
Stability of the Protactinium(V) Mono-Oxo Cation Probed by First-Principle Calculations.Chemistry (Weinheim an der Bergstrasse, Germany) · 2024Shaaban T, Réal F, Maurice R et al.DOI: 10.1002/chem.202304068
Peculiar protactinium.Nature chemistry · 2012Wilson RDOI: 10.1038/nchem.1389
Separation of protactinium from uranium-niobium alloys for (231)Pa-(235)U radiochronometry in nuclear forensic investigations.Journal of radioanalytical and nuclear chemistry · 2023Chen CY, Higginson MA, Kayzar-Boggs TM et al.DOI: 10.1007/s10967-023-08928-y
Protactinium and Actinium Monohydrides: A Theoretical Study on Their Spectroscopic and Thermodynamic Properties.The journal of physical chemistry. A · 2022de Melo GF, Dixon DADOI: 10.1021/acs.jpca.2c04690
Is the protactinium(V) mono-oxo bond weaker than what we thought?Chemical communications (Cambridge, England) · 2024Shaaban T, Oher H, Aupiais J et al.DOI: 10.1039/d4cc04522j
Protactinium Chemistry.Science (New York, N.Y.) · 1963Chetham-Strode A, Ferguson DEDOI: 10.1126/science.141.3579.444
Separation of Protactinium Employing Sulfur-Based Extraction Chromatographic Resins.Analytical chemistry · 2018Mastren T, Stein BW, Parker TG et al.DOI: 10.1021/acs.analchem.8b01380

via PubMed

Wikidata facts

Instance of: chemical element
Part of: actinide
Named after: actinium
Mass: 231.03588
Image: Protactinium-233.jpg

Show 15 more facts

atomic number: 91
element symbol: Pa
Commons category: Protactinium
topic's main category: Category:Protactinium
electronegativity: 2
Commons gallery: Protactinium
described by source: Armenian Soviet Encyclopedia
Unicode character: 鏷
canonical SMILES: [Pa]
chemical formula: Pa
time of discovery or invention: 1917-00-00
discoverer or inventor: Lise Meitner
ionic radius: 0.78
on focus list of Wikimedia project: Wikipedia:Vital articles/Level/4
topic has template: Template:Infobox protactinium

Sources (6)

via Wikidata · CC0

Article · 日本語

プロトアクチニウム (英: protactinium [ˌproʊtækˈtɪniəm]) は、原子番号91の元素。元素記号は Pa。アクチノイド元素の一つ。安定同位体は存在せず、すべてが放射性同位体である。銀白色の金属で、常温、常圧で安定な結晶構造は正方晶系であるが、800℃程に加熱すると体心立方格子が最も安定となる。比重は15.37（理論値）、融点は1575 °C、沸点は4000 °C（融点、沸点とも異なる実験値あり）。空気中での酸化はゆるやか。酸に溶ける（やや難溶）。酸素、水蒸気と反応。酸素と反応すると表面が曇る。アルカリには不溶。展性、延性があり、化学的性質は、ニオブやタンタルに類似する。安定な原子価は+5価

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