Praseodim
59
Pr
Grupă
n/a
Perioadă
6
Bloc
f
Protoni
Electroni
Neutroni
59
59
82
Proprietăți Generale
Număr atomic
59
Masă atomică
140,90765
Numar de masa
141
Categorie
Lantanide
Culoare
Argint
Radioactive
Nu
Din cuvântul grec prasios, verde și didymos, geamăn
Structură cristalină
Sistemul Hexagonal
Istoric
Praseodymium was first identified in 1885, in Vienna, by the Austrian chemist Carl Auer von Welsbach.
It was discovered in didymium, a substance incorrectly said by Carl Gustav Mosander to be a new element in 1841.
Pure metallic praseodymium was first produced in 1931.
It was discovered in didymium, a substance incorrectly said by Carl Gustav Mosander to be a new element in 1841.
Pure metallic praseodymium was first produced in 1931.
Electroni pe nivelul de energie
2, 8, 18, 21, 8, 2
Configurație electronică
[Xe] 4f3 6s2
Praseodymium is usually stored under a light mineral oil or sealed in glass
Proprietăți Fizice
Fază
Solid
Densitate
6,773 g/cm3
Punct de topire
1208,15 K | 935 °C | 1715 °F
Punct de fierbere
3793,15 K | 3520 °C | 6368 °F
Energie de fuziune
6,9 kJ/mol
Energie de evaporare
330 kJ/mol
Căldură specifică
0,193 J/g·K
Abundența în scoarța Pământului
0,00086%
Abundența în Univers
2×10-7%
Numarul CAS
7440-10-0
Număr CID PubChem
23942
Proprietăți Atomice
Rază atomică
182 pm
Rază de covalență
203 pm
Electronegativitate
1,13 (Scara lui Pauling)
Potențial de ionizare
5,473 eV
Volum molar
20,8 cm3/mol
Conductivitate termică
0,125 W/cm·K
Număr de oxidare
2, 3, 4
Aplicații
Praseodymium is used as an alloying agent with magnesium to create high-strength metals that are used in aircraft engines.
Misch metal, used in making cigarette lighters, contains about 5% praseodymium metal.
Praseodymium is used to make specialized yellow glass goggles for glass blowers and welders.
Misch metal, used in making cigarette lighters, contains about 5% praseodymium metal.
Praseodymium is used to make specialized yellow glass goggles for glass blowers and welders.
Praseodymium is considered to be moderately toxic
Izotopi
Izotopi stabili
141PrIzotopi instabili
121Pr, 122Pr, 123Pr, 124Pr, 125Pr, 126Pr, 127Pr, 128Pr, 129Pr, 130Pr, 131Pr, 132Pr, 133Pr, 134Pr, 135Pr, 136Pr, 137Pr, 138Pr, 139Pr, 140Pr, 142Pr, 143Pr, 144Pr, 145Pr, 146Pr, 147Pr, 148Pr, 149Pr, 150Pr, 151Pr, 152Pr, 153Pr, 154Pr, 155Pr, 156Pr, 157Pr, 158Pr, 159Pr