Àdàkọ:Infobox árgọ̀nù

Árgọ̀nù, ₁₈Ar

Árgọ̀nù
Pípè	/ˈɑːrɡɒn/ ​(AR-gon)
Ìhànsójú	colorless gas exhibiting a lilac/violet glow when placed in a high voltage electric field
Ìwúwo átọ̀mù Ar, std(Ar)	[39.792, 39.963] conventional: 39.95
Árgọ̀nù ní orí tábìlì àyè
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 Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver 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 Gold Mercury (element) Thallium Lead 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 Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Ne ↑ Ar ↓ Kr klorínì ← árgọ̀nù → potassium
Nọ́mbà átọ̀mù (Z)	18
Ẹgbẹ́	group 18 (noble gases)
Àyè	àyè 3
Àdìpọ̀	Àdìpọ̀-p
Ẹ̀ka ẹ́límẹ́ntì	Ẹ̀fúùfù abíire
Ìtò ẹ̀lẹ́ktrọ́nù	[Ne] 3s2 3p6
Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan	2, 8, 8
Àwọn ohun ìní ara
Ìfarahàn at STP	gas
Ìgbà ìyọ́	83.80 K ​(−189.35 °C, ​−308.83 °F)
Ígbà ìhó	87.30 K ​(−185.85 °C, ​−302.53 °F)
Kíki (at STP)	1.784 g/L
when liquid (at b.p.)	1.40 g/cm3
Triple point	83.8058 K, ​69 kPa
Critical point	150.87 K, 4.898 MPa
Heat of fusion	1.18 kJ/mol
Heat of	6.43 kJ/mol
Molar heat capacity	5R/2 = 20.786 J/(mol·K)
pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K)   47 53 61 71 87
Atomic properties
Oxidation states	0
Electronegativity	Pauling scale: no data
energies	(more)
Covalent radius	106±10 pm
Van der Waals radius	188 pm
Color lines in a spectral range Spectral lines of árgọ̀nù
Other properties
Natural occurrence	primordial
Crystal structure	​(fcc)
Speed of sound	(gas, 27 °C) 323 m/s
Thermal conductivity	17.72x10-3  W/(m·K)
Magnetic ordering	diamagnetic
CAS Number	7440–37–1
History
Discovery	Lord Rayleigh and William Ramsay (1894)
First isolation	Lord Rayleigh and William Ramsay (1894)
Main isotopes of árgọ̀nù
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct 36Ar 0.337% 36Ar is stable with 18 neutrons 37Ar syn 35 d ε 0.813 37Cl 38Ar 0.063% 38Ar is stable with 20 neutrons 39Ar trace 269 y β− 0.565 39K 40Ar 99.600% 40Ar is stable with 22 neutrons 41Ar syn 109.34 min β− 2.49 41K 42Ar syn 32.9 y β− 0.600 42K

References

This reference list does not appear in the article.