Physical Properties of Promethium

1 Physical

1.1 Melting Point

1.2 Boiling Point

1.3 Appearance

1.3.1 Physical State

1.3.2 Color

1.3.3 Luster

1.4 Hardness

1.4.1 Mohs Hardness

1.4.2 Brinell Hardness

1.4.3 Vickers Hardness

1.5 Speed of Sound

1.6 Optical Properties

1.6.1 Refractive Index

1.6.2 Reflectivity

1.7 Allotropes

1.7.1 α Allotropes

1.7.2 β Allotropes

1.7.3 γ Allotropes