Protaktinium

91
Pa
Grupp
n/a
Period
7
Block
f
Protoner
Electrons
Neutroner
91
91
140
Generella Egenskaper
Atomnummer
91
Atommassa
231,03588
Mass Number
231
Kategori
Aktinider
Färg
Silver
Radioaktiv
Ja
From the Greek protos meaning first
Kristallstruktur
Rymdcentrerat tetragonalt
Historia
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 per 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
Fysikaliska Egenskaper
Aggregationstillstånd
Fast
Densitet
15,37 g/cm3
Smältpunkt
1841,15 K | 1568 °C | 2854,4 °F
Kokpunkt
4300,15 K | 4027 °C | 7280,6 °F
Smältvärme
15 kJ/mol
Ångbildningsvärme
470 kJ/mol
Specifik värmekapacitet
-
Abundance in Earth's crust
9,9×10-13%
Abundance in Universe
n/a
Illustration
Bildkrediter: Images-of-elements
Illustration of protactinium
CAS Number
7440-13-3
PubChem CID Number
n/a
Atomära Egenskaper
Atomradie
163 pm
Kovalent radie
200 pm
Elektronegativitet
1,5 (Paulingskalan)
Jonisationspotential
5,89 eV
Molvolym
15,0 cm3/mol
Värmeledningsförmåga
0,47 W/cm·K
Oxidationstillstånd
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
Stabila isotoper
-
Instabila isotoper
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