Understanding Thulium
Thulium (chemical symbol Tm, atomic number 69) is one of the rare-earth elements, belonging to the lanthanide series in the periodic table. It is not found freely in nature but occurs in small quantities in various minerals.
Classification
Thulium is definitively classified as a metal. Specifically, it is a rare-earth metal, which are a group of 17 chemically similar metallic elements.
Physical Appearance and State
At room temperature (approximately 25°C), thulium exists as a solid. It presents a bright, silvery-gray metallic luster. When freshly cut or polished, it exhibits a distinct shine, which can tarnish slowly upon exposure to air due to oxidation. The texture of thulium is relatively soft, making it malleable (can be hammered into thin sheets) and ductile (can be drawn into wires).
Thermal Properties
The thermal properties of thulium dictate its behavior at different temperatures.
- The melting point of thulium is approximately 1545 °C. This is the temperature at which it transitions from a solid to a liquid state.
- The boiling point of thulium is approximately 1950 °C. This is the temperature at which it transitions from a liquid to a gaseous state.