- 🇬🇧 Protactinium
- 🇺🇦 Протактиній
- 🇨🇳 鏷
- 🇳🇱 Protactinium
- 🇫🇷 Protactinium
- 🇩🇪 Protactinium
- 🇮🇱 פרוטקטיניום
- 🇮🇹 Protoattinio
- 🇯🇵 プロトアクチニウム
- 🇵🇹 Protactínio
- 🇪🇸 Protactinio
- 🇸🇪 Protaktinium
- 🇷🇺 Протактиний
- Name: protactinium
- Symbol: Pa
- Atomic number: 91
- Relative atomic mass (Ar): 231.03588 (2)
- Standard state: solid at 298 K
- Appearance: silvery metallic
- Classification: Metallic
- Group in periodic table:
- Group name: Actinoid
- Period in periodic table: 7 (actinoid)
- Block in periodic table: f
- Shell structure: 2.8.18.32.20.9.2
- CAS Registry: 7440-13-3
Protactinium atoms have 91 electrons and the shell structure is 2.8.18.32.20.9.2. The ground state electronic configuration of neutral protactinium is [Rn].5f2.6d1.7s2 and the term symbol of protactinium is 4K11/2.
Protactinium: description
Protactinium has a bright metallic lustre which it retains for some time in air. The element is superconductive below 1.4 K. The element is a dangerous toxic material and requires precautions similar to those used when handling plutonium. Protactinium is one of the rarest and most expensive naturally occurring elements. The element is an α-emitter and is a radiological hazard similar to polonium. Protactinium is a highly toxic and radioactive rare earth metal that requires special handling. It is found in pitchblende and ores form Zaire and is one of the rarest and most expensive naturally occurring elements.
protactinium
This sample of uraninite contains some about 10-6 grammes of actinium at any one time. Image adapted with permission from Prof James Marshall's (U. North Texas, USA) Walking Tour of the elements CD.
Protactinium: physical properties
- Density of the chemical elements on a miniature periodic table spark table Density of solid: 15370 kg m-3
- Molar volume of the chemical elements on a miniature periodic table spark table Molar volume: 15.18 cm3
- Thermal conductivity of the chemical elements on a miniature periodic table spark table Thermal conductivity: 47 (estimate) W m‑1 K‑1
Protactinium: heat properties
- Melting point on a miniature periodic table spark table Melting point: 1841 [1568 °C (2854 °F)] K
- Boiling point on a miniature periodic table spark table Boiling point: 4300 [ca. 4000 °C (7232 °F)] K
- Enthalpy of fusion on a miniature periodic table spark table Enthalpy of fusion: 20.5 kJ mol-1
Protactinium: atom sizes
- Atomic radius (empirical) of the chemical elements on a miniature periodic table spark table Atomic radius (empirical): 180 pm
- Covalent (single bond) radius on a periodic table spark table Molecular single bond covalent radius: 169 (coordination number 5) ppm
- van der Waals radius on a periodic table spark table van der Waals radius: [ 340 ] ppm
Protactinium: electronegativities
- Pauling electronegativity of the chemical elements on a miniature periodic table spark table Pauling electronegativity: 1.5 (Pauling units)
- Allred-Rochow electronegativity of the chemical elements on a miniature periodic table spark tableAllred Rochow electronegativity: 1.14 (Pauling units)
- Mulliken-Jaffe electronegativity of the chemical elements on a miniature periodic table spark tableMulliken-Jaffe electronegativity: (no data)
Protactinium: orbital properties
- First ionization energy the chemical elements on a miniature periodic table spark table First ionisation energy: 568 kJ mol‑1
- Second ionization energy the chemical elements on a miniature periodic table spark table Second ionisation energy: 1150 kJ mol‑1
- Third ionization energy the chemical elements on a miniature periodic table spark table Third ionisation energy: 1790 kJ mol‑1
Protactinium: abundances
- Chemical elements abundance by weight in the universe on a miniature periodic table spark tableUniverse: (no data) ppb by weight
- Chemical elements abundance by weight in the earth's crust on a miniature periodic table spark tableCrustal rocks: 0.000010 ppb by weight
- Chemical elements abundance by weight in humans on a miniature periodic table spark tableHuman: (no data) ppb by weight
Protactinium: crystal structure
Protactinium: biological data
- Human abundance by weight of the chemical elements on a miniature periodic table spark table Human abundance by weight: (no data) ppb by weight
Protactinium has no biological role.
Protactinium: uses
Protactinium: reactions
Reactions of protactinium as the element with air, water, halogens, acids, and bases where known.
Protactinium: binary compounds
Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of protactinium where known.
Protactinium: compound properties
Bond strengths; lattice energies of protactinium halides, hydrides, oxides (where known); and reduction potentials where known.
Protactinium: history
Protactinium was discovered by Otto Hahn, Lise Meitner, Frederick Soddy, John Cranston in 1913 at Germany, England. Origin of name: from the Greek word "protos" meaning "first".Protactinium: isotopes
Protactinium: isolation
Isolation: coming soon!