Празеодиум

59
Pr
Група
Нема одговор
Периода
6
блок
f
Protons
Electrons
Neutrons
59
59
82
Општи Својства
Атомски број
59
Атомска тежина
140,90765
Mass Number
141
Category
Ланта­ноид
Color
Silver
Radioactive
Не
From the Greek word prasios, green, and didymos, twin
Кристална структура
Simple 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.
Electrons per shell
2, 8, 18, 21, 8, 2
Електронска конфигурација
[Xe] 4f3 6s2
Pr
Praseodymium is usually stored under a light mineral oil or sealed in glass
Физички Својства
Фаза
Solid
Густина
6,773 g/cm3
Точка на топење
1208,15 K | 935 °C | 1715 °F
Точка на вриење
3793,15 K | 3520 °C | 6368 °F
Топлина на топење
6,9 kJ/mol
Топлина на испарување
330 kJ/mol
Specific Heat Capacity
0,193 J/g·K
Abundance in Earth's crust
0,00086%
Abundance in Universe
2×10-7%
Ultrapure
Кредити на слика: Images-of-elements
Ultrapure praseodymium pieces under argon
CAS Number
7440-10-0
PubChem CID Number
23942
Атомски Својства
Атомски полупречник
182 pm
Ковалентен полупречник
203 pm
Електронегативност
1,13 (Полингова скала)
Ionization Potential
5,473 eV
Atomic Volume
20,8 cm3/mol
Thermal Conductivity
0,125 W/cm·K
Oxidation States
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
Isotopes
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