Árgọ̀nù

Árgọ̀nù
18Ar
Ne ↑ Ar ↓ Kr Tábìlì ìdásìkò klorínì ← árgọ̀nù → potassium
Ìhànsójú
colorless gas exhibiting a lilac/violet glow when placed in a high voltage electric field Spectral lines of argon
Àwọn ìdámọ́ wíwọ́pọ̀
Orúkọ, àmì-ìdámọ́, nọ́mbà	árgọ̀nù, Ar, 18
Ìpèlóhùn	/ˈɑrɡɒn/
Ẹ̀ka ẹ́límẹ̀nti	noble gases
Ẹgbẹ́, àsìkò, àdìpò	18, 3, p
Ìwúwo átọ́mù	39.948(1)
Ìtòléra ẹ̀lẹ́ktrónì	[Ne] 3s2 3p6 2, 8, 8
Ìtàn
Ìwárí	Lord Rayleigh and William Ramsay (1894)
Ìyàsọ́tọ̀ àkọ́kọ́	Lord Rayleigh and William Ramsay (1894)
Physical properties
Phase	gas
Density	(0 °C, 101.325 kPa) 1.784 g/L
Liquid density at b.p.	1.40 g·cm−3
Melting point	83.80 K, −189.35 °C, −308.83 °F
Boiling point	87.30 K, −185.85 °C, −302.53 °F
Triple point	83.8058 K (-189°C), 69 kPa
Critical point	150.87 K, 4.898 MPa
Heat of fusion	1.18 kJ·mol−1
Heat of vaporization	6.43 kJ·mol−1
Molar heat capacity	5R/2 = 20.786 J·mol−1·K−1
Vapor 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	no data (Pauling scale)
Ionization energies (more)	1st: 1520.6 kJ·mol−1
	2nd: 2665.8 kJ·mol−1
	3rd: 3931 kJ·mol−1
Covalent radius	106±10 pm
Van der Waals radius	188 pm
Miscellanea
Crystal structure	face-centered cubic
Magnetic ordering	diamagnetic
Thermal conductivity	17.72x10-3  W·m−1·K−1
Speed of sound	(gas, 27 °C) 323 m·s−1
CAS registry number	7440–37–1
Àwọn ísótòpù dídúró jùlọ
Main article: Àwọn ísótòpù árgọ̀nù
iso NA half-life DM DE (MeV) DP 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

Árgọ̀nù je elimenti kemika kan to ni ami-idamo Ar ati nomba atomu 18. O wa ninu egbe 18 (awon efuufu abiire) lori tabili idasiko awon elimenti. Argonu ni efuufu keta to wopo julo ninu afefeayika Aye, ni 0.93% (9,300 ppm), eyi so di eyi to repete ni ona bi 23.8 bi ti efuufu inu afefeayika tto wopo julo to tele, eyun dioksidi karbonu (390 ppm), ati to po repete ni ona to to 500 bi ti efuufu abiire keji to wopo, eyun neonu (18 ppm). Bi gbogbo argonu yi lo je argonu-40 radiogeniki to wa lati ituka potassium-40 ninu igbele Aye. Ni agbalaaye, argonu-36 ni isotopu argonu to wopo julo, nitoripe o je isotopu argonu to je dida pelu stellar ikojonukleu irawo ninu awon supanofa (awon irawo akomonamona).