Lithium is an alkali metal with the atomic number 3 and an atomic mass of 6.941 g/mol. It consists of 3 protons, 3 electrons, and approximately 4 neutrons. Lithium is an alkali metal characterised by its softness, flammability, and high reactivity, readily forming hydroxides. Its low density makes it the least dense solid element at standard conditions.
Lithium was first discovered in the mineral petalite by Johan August Arfwedson in 1817, with Sir Humphry Davy and W.T. Brande later isolating the element. Though rare, lithium constitutes about 0.0007% of the Earth's crust in its mineral form. Its compounds have long been used in specific types of glass and porcelain. In recent years, lithium has gained increased importance for its role in dry-cell batteries and nuclear reactors. Additionally, certain lithium compounds are prescribed to treat bipolar disorder.
Because of its reactivity, lithium reacts both with organic and inorganic substances. Because of its placement in Group 1 of the periodic table, lithium has a high degree of reactivity, particularly when it comes to non-metals like oxygen, nitrogen, and halogens, as seen by the following reactions.
4Li + O₂ -> 2Li₂O
Li₂O → 2LiCl + H₂O + 2HCl
4LiOH + H₂ = 2Li₂O + 2H₂O
6Li + N₂ → 2Li₃N
Rechargeable batteries, which power gadgets like cell phones, computers, digital cameras, and electric cars, are the main application for lithium.
Non-rechargeable batteries for gadgets like toys, clocks, and heart pacemakers also include lithium.
Lithium-Aluminum Alloys: Used in high-speed trains, bicycle frames, and airplanes, these alloys increase the strength and decrease the weight of aluminum.
Magnesium-lithium alloys: Armour plating is done using magnesium-lithium alloys that have been strengthened.
Lithium oxide enhances the qualities of unique glasses and glass ceramics.
One of the materials that is most hygroscopic is lithium chloride (LiCl). It is utilized in industrial drying systems and air conditioning systems.
Lithium Stearate: This lubricant can be used for any purpose and works especially well at high temperatures.
Lithium carbonate is a common ingredient in drugs used for treatment of bipolar disorder and manic depression.
Lithium Hydride (LiH): A fuel source that can be utilized to store hydrogen.
(Session 2025 - 26)