Understanding Thallium: Physical Characteristics
Thallium (Tl) is a chemical element with atomic number 81. It belongs to Group 13 of the periodic table, alongside elements like Boron and Aluminium.
Classification of Thallium
Thallium is classified as a metal. It exhibits characteristic metallic properties, although some of its properties distinguish it from typical heavy metals.
Physical Appearance
Color
When freshly cut, thallium displays a metallic luster with a silvery-white or bluish-white appearance. However, it tarnishes rapidly upon exposure to air, developing a dull grey or bluish-grey oxide layer, similar to lead. This rapid oxidation obscures its bright metallic sheen.
Texture and Luster
Thallium is an exceptionally soft and malleable metal, easily cut with a knife at room temperature. It is also ductile, meaning it can be drawn into a wire. Despite its softness, a fresh surface reflects light with a distinct metallic luster.
State of Matter and Thermal Properties
State at Room Temperature
At standard room temperature (approximately 25°C), thallium exists as a solid.
Melting and Boiling Points
Thallium has a relatively low melting point for a metal.
- Melting Point: 303.5 °C
- Boiling Point: 1473 °C