Heliumo
2
He
Grupo
18
Perio
1
Bloko
s
Protonoj
Elektronoj
Neŭtronoj
2
2
2
Ĝeneralaj Propraĵoj
Atoma Nombro
2
Atommaso
4,002602
Amasa Nombro
4
Kategorio
Noblaj gasoj
Koloro
Senkolora
Radioaktiva
Ne
De la Greka vorto helios, la suno
Kristala Strukturo
Vizaĝo Centrita Kubo
Historio
French astronomer Jules Janssen obtained the first evidence of helium during the solar eclipse of 1868.
Norman Lockyer and Edward Frankland suggested the name helium for the new element.
In 1895, Sir William Ramsay discovered helium in the uranium mineral cleveite.
It was independently discovered in cleveite by Per Teodor Cleve and Abraham Langlet.
Norman Lockyer and Edward Frankland suggested the name helium for the new element.
In 1895, Sir William Ramsay discovered helium in the uranium mineral cleveite.
It was independently discovered in cleveite by Per Teodor Cleve and Abraham Langlet.
Elektronoj per ŝelo
2
Elektrona Agordo
1s2
Unlike any other element, helium will remain liquid down to absolute zero at normal pressures
Fizikaj Propraĵoj
Fazo
Gasa
Denso
0,0001785 g/cm3
Fandpunkto
0,95 K | -272,2 °C | -457,96 °F
Bolpunkto
4,22 K | -268,93 °C | -452,07 °F
Varmo de Fuzio
0,02 kJ/mol
Varmo de Vaporiĝo
0,083 kJ/mol
Specifa Varmo Kapacito
5,193 J/g·K
Krusta Abundo
5,5×10-7%
Universa Abundo
23%
CAS Nombro
7440-59-7
PubChem Kunmetita Identiga Nombro
23987
Atomaj Propraĵoj
Atoma Radiuso
31 pm
Kovalenta Radiuso
28 pm
Elektronegativeco
-
Potencialo de jonigo
24,5874 eV
Atoma Volumo
27,2 cm3/mol
Termika Kondukto
0,00152 W/cm·K
Oksidaj Ŝtatoj
0
Aplikoj
Helium is used as a protective gas in growing silicon and germanium crystals, in titanium and zirconium production, and in gas chromatography.
Helium at low temperatures is used in cryogenics.
Helium is used for filling balloons and for pressurizing liquid fuel rockets.
Helium is used as a shielding gas in arc welding processes.
Helium at low temperatures is used in cryogenics.
Helium is used for filling balloons and for pressurizing liquid fuel rockets.
Helium is used as a shielding gas in arc welding processes.
Helium is not known to be toxic
Izotopoj
Stabilaj Izotopoj
3He, 4HeMalstabilaj Isotopoj
5He, 6He, 7He, 8He, 9He, 10He