# Praseodymium

59

Pr

Group

n/a

Period

6

Block

f

Protons

Electrons

Neutrons

59

59

82

General Properties

Atomic Number

59

Atomic Weight

140.90765

Mass Number

141

Category

Lanthanides

Colour

Silver

Radioactive

No

From the Greek word

*prasios*, green, and*didymos*, twinCrystal Structure

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.

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

Electron Configuration

[Xe] 4f

^{3}6s^{2}Praseodymium is usually stored under a light mineral oil or sealed in glass

Physical Properties

Phase

Solid

Density

6.773 g/cm

^{3}Melting Point

1208.15 K | 935 °C | 1715 °F

Boiling Point

3793.15 K | 3520 °C | 6368 °F

Heat of Fusion

6.9 kJ/mol

Heat of Vaporization

330 kJ/mol

Specific Heat Capacity

0.193 J/g·K

Abundance in Earth's crust

0.00086%

Abundance in Universe

2×10

^{-7}%CAS Number

7440-10-0

PubChem CID Number

23942

Atomic Properties

Atomic Radius

182 pm

Covalent Radius

203 pm

Electronegativity

1.13 (Pauling scale)

Ionization Potential

5.473 eV

Atomic Volume

20.8 cm

^{3}/molThermal 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.

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

^{141}PrUnstable Isotopes

^{121}Pr,^{122}Pr,^{123}Pr,^{124}Pr,^{125}Pr,^{126}Pr,^{127}Pr,^{128}Pr,^{129}Pr,^{130}Pr,^{131}Pr,^{132}Pr,^{133}Pr,^{134}Pr,^{135}Pr,^{136}Pr,^{137}Pr,^{138}Pr,^{139}Pr,^{140}Pr,^{142}Pr,^{143}Pr,^{144}Pr,^{145}Pr,^{146}Pr,^{147}Pr,^{148}Pr,^{149}Pr,^{150}Pr,^{151}Pr,^{152}Pr,^{153}Pr,^{154}Pr,^{155}Pr,^{156}Pr,^{157}Pr,^{158}Pr,^{159}Pr