Πρωτακτίνιο

91
Pa
Ομάδα
n/a
Περίοδος
7
Τομέας
f
Πρωτονίων
Electrons
Νετρονίων
91
91
140
General Properties
Ατομικός Αριθμός
91
Ατομικό βάρος
231,03588
Mass Number
231
Κατηγορία
Ακτινίδες
Χρώμα
Silver
Radioactive
Ναι
From the Greek protos meaning first
Κρυσταλλικό σύστημα
Centered Tetragonal
Ιστορία
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.
Electrons per shell
2, 8, 18, 32, 20, 9, 2
Ηλεκτρονική διαμόρφωση
[Rn] 5f2 6d1 7s2
Pa
Protactinium is one of the rarest and most expensive naturally occurring elements
Physical Properties
Phase
Στερεά
Πυκνότητα
15,37 g/cm3
Σημείο τήξης
1841,15 K | 1568 °C | 2854,4 °F
Σημείο βρασμού
4300,15 K | 4027 °C | 7280,6 °F
Heat of Fusion
15 kJ/mol
Heat of Vaporization
470 kJ/mol
Ειδική θερμοχωρητικότητα
-
Abundance in Earth's crust
9,9×10-13%
Abundance in Universe
n/a
Illustration
Image Credits: Images-of-elements
Illustration of protactinium
CAS Number
7440-13-3
PubChem CID Number
n/a
Atomic Properties
Ατομική ακτίνα
163 pm
Ομοιοπολική ακτίνα
200 pm
Ηλεκτραρνητικότητα
1,5 (Κλίμακα Pauling)
Ionization Potential
5,89 eV
Atomic Volume
15,0 cm3/mol
Θερμική αγωγιμότητα
0,47 W/cm·K
Oxidation States
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
Ισότοπα
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