Protactinium

91
Pa
Gruppe
n/a
Periode
7
Blok
f
Protons
Electrons
Neutrons
91
91
140
General Properties
Atomnummer
91
Atommasse
231,03588
Mass Number
231
Kategori
Actinider
Farve
Silver
Radioactive
Ja
From the Greek protos meaning first
Krystalstruktur
Rumcentreret Tetragonal
History
In 1900, William Crookes isolated protactinium as an intensely radioactive material from uranium

Protactinium was first identified in 1913 by Kasimir Fajans and Oswald Helmuth Göhring in Germany.

A more stable isotope of protactinium was discovered in 1917 by Otto Hahn and Lise Meitner at the Kaiser Wilhelm Institute in Berlin.
Elektroner i hver skal
2, 8, 18, 32, 20, 9, 2
Elektronkonfiguration
[Rn] 5f2 6d1 7s2
Pa
Protactinium is one of the rarest and most expensive naturally occurring elements
Physical Properties
Tilstandsform
Fast stof
Massefylde
15,37 g/cm3
Smeltepunkt
1841,15 K | 1568 °C | 2854,4 °F
Kogepunkt
4300,15 K | 4027 °C | 7280,6 °F
Smeltevarme
15 kJ/mol
Fordampningsvarme
470 kJ/mol
Varmefylde
-
Abundance in Earth's crust
9,9×10-13%
Abundance in Universe
n/a
Illustration
Billede akkrediteringer: Images-of-elements
Illustration of protactinium
CAS Number
7440-13-3
PubChem CID Number
n/a
Atomic Properties
Atomradius
163 pm
Kovalent radius
200 pm
Elektronegativitet
1,5 (Paulings skala)
Ionization Potential
5,89 eV
Atomic Volume
15,0 cm3/mol
Varmeledningsevne
0,47 W/cm·K
Oxidationstrin
3, 4, 5
Applications
Owing to its scarcity, high radioactivity and high toxicity, there are currently no uses for protactinium outside of scientific research.

With the advent of highly sensitive mass spectrometers, an application of 231Pa as a tracer in geology and paleoceanography has become possible.

Protactinium-231 combined with the thorium-230 can be used to date marine sediments.
Protactinium is toxic and highly radioactive
Isotoper
Stable Isotopes
-
Unstable Isotopes
212Pa, 213Pa, 214Pa, 215Pa, 216Pa, 217Pa, 218Pa, 219Pa, 220Pa, 221Pa, 222Pa, 223Pa, 224Pa, 225Pa, 226Pa, 227Pa, 228Pa, 229Pa, 230Pa, 231Pa, 232Pa, 233Pa, 234Pa, 235Pa, 236Pa, 237Pa, 238Pa, 239Pa, 240Pa