Protaktinium
91
Pa
Skupina
n/a
Perioda
7
Blok
f
Protony
Elektrony
Neutrony
91
91
140
Hlavní vlastnosti
Atomové číslo
91
Atomová hmotnost
231,03588
Hmotnostní číslo
231
Kategorie
Aktinoidy
Barva
Stříbrná
Radioaktivní
Ano
From the Greek protos meaning first
Krystalografická soustava
Tetragonální
Historie
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.
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.
Elektronů v obalu
2, 8, 18, 32, 20, 9, 2
Elektronová konfigurace
[Rn] 5f2 6d1 7s2
Protactinium is one of the rarest and most expensive naturally occurring elements
Fyzické vlastnosti
Skupenství
Pevná
Hustota
15,37 g/cm3
Teplota tání
1841,15 K | 1568 °C | 2854,4 °F
Teplota varu
4300,15 K | 4027 °C | 7280,6 °F
Skupenské teplo tání
15 kJ/mol
Skupenské teplo varu
470 kJ/mol
Měrná tepelná kapacita
-
Hojnost v zemské kůře
9,9×10-13%
Hojnost ve vesmíru
n/a
Číslo CAS
7440-13-3
PubChem CID číslo
n/a
Atomové vlastnosti
Atomový poloměr
163 pm
Kovalentní poloměr
200 pm
Elektronegativita
1,5 (Paulingova stupnice)
Ionizační potenciál
5,89 eV
Molární objem
15,0 cm3/mol
Tepelná vodivost
0,47 W/cm·K
Oxidační čísla
3, 4, 5
Aplikace
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.
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.
Protaktinium je toxické a vysoce radioaktivní
Izotopy
Stabilní izotopy
-Nestabilní izotopy
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