Quick Facts
| Property | Value |
|---|---|
| Symbol | Li |
| Atomic Number | 3 |
| Atomic Mass | 6.94 u |
| Category | Alkali Metal |
| Period | 2 |
| Group | 1 |
| Block | s |
| Electron Configuration | [He] 2s¹ |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 0.534 g/cm³ |
| Melting Point | 180.50°C (453.65 K) |
| Boiling Point | 1342°C (1615 K) |
| Appearance | Soft, silvery-white metal |
Atomic Properties
| Property | Value |
|---|---|
| Electron Configuration | [He] 2s¹ |
| Electronegativity | 0.98 (Pauling scale) |
| First Ionization Energy | 520.2 kJ/mol |
| Atomic Radius | 152 pm |
| Covalent Radius | 128 pm |
| Van der Waals Radius | 182 pm |
History and Discovery
Discovered by: Johan August Arfwedson Year of Discovery: 1817 Location: Stockholm, Sweden
Etymology
The name "lithium" comes from the Greek word "lithos" meaning "stone," as it was discovered in a mineral (petalite), unlike sodium and potassium which were discovered in plant materials.
Discovery Story
Johan August Arfwedson discovered lithium in 1817 while analyzing petalite ore in the laboratory of Jöns Jacob Berzelius. He detected a new alkali metal but could not isolate it. In 1821, William Thomas Brande first isolated lithium metal through electrolysis of lithium oxide. Later in 1855, Robert Bunsen and Augustus Matthiessen produced larger quantities through electrolysis of lithium chloride.
Isotopes
| Isotope | Natural Abundance | Half-life | Decay Mode |
|---|---|---|---|
| ⁶Li | 7.59% | Stable | - |
| ⁷Li | 92.41% | Stable | - |
Occurrence
Natural Abundance
Lithium is relatively rare, making up about 20 ppm of the Earth's crust. It is never found free in nature due to its high reactivity. Major sources include mineral deposits (spodumene, petalite, lepidolite) and brine deposits in salt flats, particularly in South America's "Lithium Triangle" (Chile, Argentina, Bolivia).
Extraction and Production
- Brine Extraction: Pumping lithium-rich brine into evaporation ponds (South America, China)
- Hard Rock Mining: Extracting from spodumene and other lithium-bearing minerals (Australia)
- Processing: Usually produces lithium carbonate (Li₂CO₃) or lithium hydroxide (LiOH)
Applications and Uses
Industrial Applications
- Lithium-ion batteries (smartphones, laptops, electric vehicles)
- Ceramics and glass manufacturing (reduces melting temperature)
- Lubricating greases
- Aluminum production (flux)
Medical Applications
- Lithium carbonate and lithium citrate for treating bipolar disorder
- Mood stabilizer for psychiatric conditions
- Research into Alzheimer's disease treatment
Technological Applications
- Battery technology (highest electrochemical potential of any element)
- Nuclear fusion research (lithium-6 breeding tritium)
- Air purification (CO₂ absorption in spacecraft)
Other Uses
- Fireworks and flares (produces bright red color)
- Metallurgy (degasifier in copper and steel)
- Polymers (initiator for synthetic rubber production)
Biological Role
Lithium has no established essential biological function, though trace amounts are present in organisms. Some studies suggest it may influence mood and neurological function.
In the Human Body
- Present in trace amounts in all organs
- May influence neurological pathways
- Therapeutic use in treating bipolar disorder affects neurotransmitter signaling
Dietary Sources
Small amounts are found in grains, vegetables, and drinking water. Daily intake is typically 0.1-3 mg.
Safety and Hazards
Toxicity
Lithium has a narrow therapeutic index. At high doses, it can cause lithium toxicity affecting the nervous system, kidneys, and thyroid. Symptoms include tremors, nausea, confusion, and in severe cases, seizures.
Handling Precautions
- Highly reactive with water and moisture (reacts less violently than sodium)
- Store under oil or inert atmosphere
- Can cause skin burns
- Fire hazard—reacts with nitrogen, oxygen, and water
- Use class D fire extinguisher for lithium fires
Environmental Impact
Lithium mining and processing can impact local water resources. Battery recycling is becoming increasingly important as lithium demand grows.
Interesting Facts
- Lithium is the lightest metal and the least dense solid element
- It is soft enough to cut with a knife
- Lithium floats on water while reacting with it
- The global demand for lithium has surged due to electric vehicle batteries
- Lithium was one of the three elements produced in the Big Bang (along with hydrogen and helium)