Jul 11 2013
Topics Covered
Introduction
Chemical Properties
Physical Properties
Mechanical Properties
Thermal Properties
Applications
Introduction
Lithium is a chemical element with Li as its symbol. It belongs to group 1 and period 2 of the periodic table and has an atomic number of 3. It is a part of the alkali metal group of chemical elements.
Lithium was initially found in the mineral petalite. It has also been found in the minerals spodumene and lepidolite.
Lithium has the highest specific heat of any solid element, and is the lightest known metal. It can be readily alloyed with copper, manganese, aluminum, and cadmium to make strong alloys. Lithium is silvery-white in color.
Lithium is soluble in short chain aliphatic amines but is insoluble in hydrocarbons.
Chemical Properties
The chemical properties of lithium are provided in the table below.
|
Chemical Data |
|
CAS number |
7439-93-2 |
|
Thermal neutron cross section |
70 barns/atom |
|
Electrode potential |
-3.02 V |
|
Ionic radius |
0.680 Å |
|
Electronegativity |
0.98 |
|
X-ray absorption edge |
226.62 Å |
|
Electrochemical equivalent |
0.262 g/A/h |
Physical Properties
The following table discusses the physical properties of lithium.
|
Properties |
Metric |
Imperial |
|
Density |
0.530 g/cm3 |
0.0191 lb/in3 |
|
Melting point |
181°C |
358°F |
|
Boiling point |
1342 °C |
2448°F |
Mechanical Properties
The mechanical properties of lithium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
≤ 15 MPa |
≤ 2180 psi |
|
Hardness, Vickers |
≤ 5 |
≤ 5 |
Thermal Properties
The thermal properties of lithium are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@20-100°C/68-212°F) |
56 µm/m°C |
31.1 µin/in°F |
|
Thermal conductivity |
71.2 W/mK |
494 BTU in/hr.ft².°F |
Applications
Lithium is widely used in heat transfer applications.
The following are the other application areas of lithium:
-
To make special glasses and ceramics
-
In electrical and electronic components
-
To make lubricating greases
-
As a flux for welding or soldering.
Lithium can be formed into many useful compounds. Some are listed below with their specific application areas:
-
Lithium fluoride - in specialist optics for IR, UV and vacuum UV applications
-
Lithium niobate - in non-linear optics applications
-
Lithium chloride and lithium bromide - used as desiccants for gas streams.