Classification of Lithium
Lithium is classified as an alkali metal, belonging to Group 1 of the periodic table. This places it firmly within the category of metals, rather than non-metals or metalloids.
Physical Properties of Lithium
State, Color, and Luster
At standard room temperature (approximately 25°C), lithium exists as a solid. It is a silvery-white metal with a distinct metallic luster when its surface is freshly cut. Upon exposure to air, this luster rapidly diminishes as the surface reacts with oxygen and moisture, forming a dull, greyish layer of lithium oxide and lithium hydroxide.
Texture and Density
Lithium exhibits a remarkably soft texture for a metal. It is soft enough to be easily cut with a knife, demonstrating a lower hardness compared to many other metals. This softness is a characteristic feature of alkali metals. Furthermore, lithium holds the distinction of being the least dense solid element. Its low density contributes to its utility in applications where lightweight materials are crucial, such as in the rechargeable batteries powering mobile phones, laptops, and the growing fleet of electric vehicles and e-rickshaws across India.
Melting and Boiling Points
Lithium has a relatively low melting point compared to most other metals. It transitions from a solid to a liquid state at approximately 180.5 °C. Its boiling point is significantly higher, reaching about 1342 °C, at which temperature it changes from a liquid to a gaseous state.