Praseodymium

59
Pr
Gruppe
n/a
Periode
6
Blok
f
Protons
Electrons
Neutrons
59
59
82
General Properties
Atomnummer
59
Atommasse
140,90765
Mass Number
141
Kategori
Lantanider
Farve
Silver
Radioactive
Nej
From the Greek word prasios, green, and didymos, twin
Krystalstruktur
Simpel Hexagonal
History
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.
Elektroner i hver skal
2, 8, 18, 21, 8, 2
Elektronkonfiguration
[Xe] 4f3 6s2
Pr
Praseodymium is usually stored under a light mineral oil or sealed in glass
Physical Properties
Tilstandsform
Fast stof
Massefylde
6,773 g/cm3
Smeltepunkt
1208,15 K | 935 °C | 1715 °F
Kogepunkt
3793,15 K | 3520 °C | 6368 °F
Smeltevarme
6,9 kJ/mol
Fordampningsvarme
330 kJ/mol
Varmefylde
0,193 J/g·K
Abundance in Earth's crust
0,00086%
Abundance in Universe
2×10-7%
Ultrapure
Billede akkrediteringer: Images-of-elements
Ultrapure praseodymium pieces under argon
CAS Number
7440-10-0
PubChem CID Number
23942
Atomic Properties
Atomradius
182 pm
Kovalent radius
203 pm
Elektronegativitet
1,13 (Paulings skala)
Ionization Potential
5,473 eV
Atomic Volume
20,8 cm3/mol
Varmeledningsevne
0,125 W/cm·K
Oxidationstrin
2, 3, 4
Applications
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.
Praseodymium is considered to be moderately toxic
Isotoper
Stable Isotopes
141Pr
Unstable Isotopes
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