Protactiniu
91
Pa
Grupă
n/a
Perioadă
7
Bloc
f
Protoni
Electroni
Neutroni
91
91
140
Proprietăți Generale
Număr atomic
91
Masă atomică
231,03588
Numar de masa
231
Categorie
Actinide
Culoare
Argint
Radioactive
Da
Din greacă protos, însemnând primul
Structură cristalină
Centrat Tetragonal
Istoric
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.
Electroni pe nivelul de energie
2, 8, 18, 32, 20, 9, 2
Configurație electronică
[Rn] 5f2 6d1 7s2
Protactinium is one of the rarest and most expensive naturally occurring elements
Proprietăți Fizice
Fază
Solid
Densitate
15,37 g/cm3
Punct de topire
1841,15 K | 1568 °C | 2854,4 °F
Punct de fierbere
4300,15 K | 4027 °C | 7280,6 °F
Energie de fuziune
15 kJ/mol
Energie de evaporare
470 kJ/mol
Căldură specifică
-
Abundența în scoarța Pământului
9,9×10-13%
Abundența în Univers
n/a
Numarul CAS
7440-13-3
Număr CID PubChem
n/a
Proprietăți Atomice
Rază atomică
163 pm
Rază de covalență
200 pm
Electronegativitate
1,5 (Scara lui Pauling)
Potențial de ionizare
5,89 eV
Volum molar
15,0 cm3/mol
Conductivitate termică
0,47 W/cm·K
Număr de oxidare
3, 4, 5
Aplicații
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.
Protactinium is toxic and highly radioactive
Izotopi
Izotopi stabili
-Izotopi instabili
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