The chemical and physical properties of lithium or element 3

Lithium, which was classified as an alkali metal, was discovered by Johan August Arfwedson in 1817. It happened while he was observing that when he burned a petalite mineral, it gave off a bright red flame. Intrigued by what he saw, he did several investigations in which it was discovered that a substance behaved like an alkali metal. However, this metal, at that time, was lighter than sodium.

Later, in 1821, the English chemist William Brande obtained a small sample of pure lithium, but this was not enough to make further measurements. It was not until 1855 that large quantities of pure lithium could be produced. These advances were achieved thanks to the chemists Robert Bunsen and Augustus Matthiessen, German and British, respectively.

Basic Lithium Facts

Arfwedson named his alkali metal after a stone (from the Greek lithos ) to reflect its origin.

1. Atomic number : 3
2. Symbol : Li
3. Atomic mass : 6.941 g.mol ^-1
4. Atomic weight : [6.938; 6,997]
5. Density : 0.53 g.cm ^-3 at 20°C
6. Electron configuration : 1s ² 2s ¹ or [He]2s ¹
7. Reference : IUPAC 2009
8. It is the first of the alkalis in the periodic table and in nature it is found in a mixture of Li6 and Li7 isotopes.

Lithium Properties

Among the most significant properties that lithium possesses, the following stand out: its high heat capacity, having the highest specific heat of any solid element. Its wide temperature range in liquid state; its great thermal conductivity. Lithium is the lightest solid metal, having about half the density of water. It has a low melting point (180.54 C) and a boiling point of 1342 C.

On the other hand, the specific gravity of lithium is 0.534 (20 C) and its valence is 1. Metallic lithium has a silvery appearance, is soluble in short-chain aliphatic amines, and is insoluble in hydrocarbons. This metal has a large number of reactions, it does react with water, but not as vigorously as sodium. Likewise, it reacts with oxygen to form monoxide and peroxide and is the only alkali metal capable of reacting with nitrogen at room temperature. Therefore, this metal should be stored in mineral oil. Elemental lithium is extremely flammable, yet it is less reactive and explosive than the other alkali metals.

Uses or applications of lithium

Both lithium and its components have been used over the years for different activities. We will mention a few:

1. As already mentioned, metallic lithium has the highest specific heat of all solid elements. For this reason, this metal has high applications in heat transfer.
2. Lithium stearate is mixed with oils to make multi-purpose lubricants. Also, to generate high temperatures.
3. Lithium hydroxide is used to absorb carbon dioxide in space vehicles.
4. Lithium can be alloyed with aluminum, copper, manganese, and cadmium to make high-performance aircraft alloys.
5. Lithium is sometimes used as a material for battery anodes due to its high electrochemical potential. Its compounds are used in dry cells and storage batteries.
6. Lithium chloride and lithium bromide are highly hygroscopic, which is why they are used as drying agents.
7. Lithium is also used in the manufacture of special high-resistance glasses and ceramics. Lithium-based compounds (such as lithium carbon Li2CO3) are sometimes used for pharmaceuticals. In fact, lithium is approved by the US Food and Drug Administration (FDA) as a prescription medication for use in bipolar disorder.

lithium sources

Lithium is not a metal found free in nature. However, it is found in small amounts in virtually all igneous rocks and mineral spring waters. That being said, minerals that contain lithium are lepidolite, petalite, amblygonite, and spodumene. On the other hand, metallic lithium is produced electrolytically from molten chloride.

Lithium Physical Data

1. Isotopes :  8 isotopes [Li- ₄ to Li- ₁₁ ]. Li-6 (7.59% abundance) and Li-7 (92.41% abundance) are both stable.
2. Atomic radius (pm):  155
3. Atomic Volume (cc/mol):  13.1
4. Covalent radius (pm):  163
5. Ionic radius :  68 (+1e)
6. Heat: Specific (@ 20°CJ/g mol):  3.489; melting (kJ/mol):  2.89; evaporation rate (kJ/mol):  148
7. Debye temperature (°K):  400.00
8. Pauling Negativity Number:  0.98
9. First ionizing energy (kJ/mol):  519.9
10. Oxidation states :  1
11. Lattice Structure:  Body-Centered Cubic
12. Lattice constant (Å):  3.490
13. Magnetic order:  paramagnetic
14. Electrical resistivity (20°C):  92.8 nΩ m
15. Thermal conductivity (300 K):  84.8 W m−1 K−1
16. Thermal expansion (25°C):  46 µm m−1 K−1
17. Speed ​​of sound (thin rod) (20°C):  6000 m/s
18. Modulus : Young’s:  4.9 GPa; cut-off:  4.2 GPa; bulk:  11 GPa.
19. Mohs hardness :  0.6

Sources

1. Los Alamos National Laboratory (2001)
2. IUPAC 2009
3. Crescent Chemical Company (2001)
4. Lange’s Handbook of Chemistry (1952)