Lithium

Lithium (frae Greek: λίθος, romanised: lithos, lit. 'stane') is a chemical element wi symbol Li an atomic nummer 3. It is a saft, siller-white metal belangin tae the alkali metal group o chemical elements. Unner staundart condeetions, it is the lichtest metal annthe lichtest solit element. Lik aw alkali metals, lithium is heichly reactive an flammable, an is stored in mineral ile. Whan cut, it exhibits a metallic luster, but weet air corrodes it quickly tae a dull sillery gray, then black tarnish. It niver occurs freely in naitur, but anly in (uisually ionic) compoonds, sic as pegmatitic minerals, that war ance the main soorce o lithium. Due tae its solubility as an ion, it is present in ocean watter an is commonly obteened frae brines. Lithium metal is isolatit electrolytically frae a mixtur o lithium chloride an potassium chloride.

Lithium, ₃Li

Lithium floatin in ile
Lithium
Pronunciation	/ˈlɪθiəm/ ​(LITH-ee-əm)
Appearance	silvery-white
Standard atomic weight Ar, std(Li)	[7000693800000000000♠6.938, 7000699700000000000♠6.997] conventional: 7000694000000000000♠6.94
Lithium in the periodic cairt
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gowd Mercur (element) Thallium Leid (element) Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium H ↑ Li ↓ Na helium ← lithium → beryllium
Atomic nummer (Z)	3
Group	group 1 (alkali metals)
Period	period 2
Block	s-block
Element category	Alkali metal
Electron confeeguration	[He] 2s1
Electrons per shell	2, 1
Pheesical properties
Phase at STP	solit
Meltin pynt	453.65 K ​(180.50 °C, ​356.90 °F)
Bylin pynt	1603 K ​(1330 °C, ​2426 °F)
Density (near r.t.)	0.534 g/cm3
when liquid (at m.p.)	0.512 g/cm3
Creetical pynt	3220 K, 67 MPa (extrapolatit)
Heat o fusion	3.00 kJ/mol
Heat o vapourisation	136 kJ/mol
Molar heat capacity	24.860 J/(mol·K)
Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 797 885 995 1144 1337 1610
Atomic properties
Oxidation states	+1 strangly basic
Electronegativity	Pauling scale: 0.98
Ionisation energies	1st: 520.2 kJ/mol 2nd: 7298.1 kJ/mol 3rd: 11815.0 kJ/mol
Atomic radius	empirical: 152 pm
Covalent radius	128±7 pm
Van der Waals radius	182 pm
Colour lines in a spectral range Spectral lines o lithium
Ither properties
Naitural occurrence	primordial
Creestal structur	​body-centred cubic (bcc)
Speed o soond thin rod	6000 m/s (at 20 °C)
Thermal expansion	46 µm/(m·K) (at 25 °C)
Thermal conductivity	84.8 W/(m·K)
Electrical resistivity	92.8 nΩ·m (at 20°C)
Magnetic orderin	paramagnetic
Young's modulus	4.9 GPa
Shear modulus	4.2 GPa
Bulk modulus	11 GPa
Mohs haurdness	0.6
CAS Nummer	7439-93-2
History
Diskivery	Johan August Arfwedson (1817)
First isolation	William Thomas Brande (1821)
Main isotopes o lithium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 6Li 7.5% stable 7Li 92.5% stable
6Li content mey be as law as 3.75% in naitural samples. 7Li would tharefor hae a content o up tae 96.25%.

The nucleus o the lithium atom verges on instability, syne the twa stable lithium isotopes foond in nature hae amang the lawest bindin energies per nucleon o aw stable nuclides. Acause o its relative nuclear instability, lithium is less common in the solar seestem nor 25 o the first 32 chemical elements even tho its nuclei are verra li ht: it is an exception tae the trend that hivier nuclei are less common. For relatit raisons, lithium haes important uises in nuclear physics. The transmutation o lithium atoms tae helium in 1932 wis the first fully man-made nuclear reaction, an lithium deuteride serves as a fusion fuel in staged thermonuclear wappens.

Lithium an its compoonds hae several industrial applications, includin heat-resistant gless an ceramics, lithium grease lubricants, flux additives for airn, steel an aluminium production, lithium batteries, an lithium-ion batteries. The uises consume mair nor three quarters o lithium production.

Lithium battery

Lithium is present in biological seestems in trace amoonts; its functions are uncertaint. Lithium sauts hae pruiven tae be uisefu as a muid-stabilising drog in the treatment o bipolar disorder in humans.