Beryllium

Beryllium is a chemical element wi seembol Be an atomic nummer 4. It is creaut throu stellar nucleosynthesis an is a relatively rare element in the universe. It is a divalent element that occurs naiturally anerly in combination wi ither elements an minerals. Notable gemstanes whilk contain beryllium include beryl (aquamarine, emerald) an chrysoberyl. As a free element, it is a steel-gray, strang, lichtwicht an brickle alkaline yird metal.

Beryllium, ₄Be

Beryllium
Pronunciation	/bəˈrɪliəm/ ​(bə-RIL-ee-əm)
Appearance	white-gray metallic
Standard atomic weight Ar, std(Be)	7000901218310000000♠9.0121831(5)
Beryllium 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 – ↑ Be ↓ Mg lithium ← beryllium → boron
Atomic nummer (Z)	4
Group	group 2 (alkaline yird metals)
Period	period 2
Block	s-block
Element category	Alkaline yird metal
Electron confeeguration	[He] 2s2
Electrons per shell	2, 2
Pheesical properties
Phase at STP	solit
Meltin pynt	1560 K ​(1287 °C, ​2349 °F)
Bylin pynt	3243 K ​(2970 °C, ​5378 °F)
Density (near r.t.)	1.85 g/cm3
when liquid (at m.p.)	1.690 g/cm3
Creetical pynt	5205 K,  MPa (extrapolatit)
Heat o fusion	12.2 kJ/mol
Heat o vapourisation	292 kJ/mol
Molar heat capacity	16.443 J/(mol·K)
Vapour pressur P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 1462 1608 1791 2023 2327 2742
Atomic properties
Oxidation states	0, +1, +2 (an amphoteric oxide)
Electronegativity	Pauling scale: 1.57
Ionisation energies	1st: 899.5 kJ/mol 2nd: 1757.1 kJ/mol 3rd: 14848.7 kJ/mol (more)
Atomic radius	empirical: 112 pm
Covalent radius	96±3 pm
Van der Waals radius	153 pm
Colour lines in a spectral range Spectral lines o beryllium
Ither properties
Naitural occurrence	primordial
Creestal structur	​hexagonal close-packed (hcp)
Speed o soond thin rod	12890 m/s (at r.t.)
Thermal expansion	11.3 µm/(m·K) (at 25 °C)
Thermal conductivity	200 W/(m·K)
Electrical resistivity	36 nΩ·m (at 20 °C)
Magnetic orderin	diamagnetic
Young's modulus	287 GPa
Shear modulus	132 GPa
Bulk modulus	130 GPa
Poisson ratio	0.032
Mohs haurdness	5.5
Vickers haurdness	1670 MPa
Brinell haurdness	590–1320 MPa
CAS Nummer	7440-41-7
History
Diskivery	Louis Nicolas Vauquelin (1797)
First isolation	Friedrich Wöhler & Antoine Bussy (1828)
Main isotopes o beryllium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 7Be trace 53.12 d ε 7Li γ – 9Be 100% stable 10Be trace 1.36×106 y β− 10B