Argon

18
Ar
Golongan
18
Periode
3
Blok
p
Proton
Elektron
Neutron
18
18
22
Sifat Umum
Nomor atom
18
Massa atom
39,948
Nomor massa
40
Kategori
Gas mulia
Warna
Tak berwarna
Radioaktif
Tidak
From the Greek argos, inactive
Struktur kristal
Kubik Berpusat-muka
Sejarah
Argon was suspected to be present in air by Henry Cavendish in 1785.

It was not isolated until 1894 by Lord Rayleigh and Sir William Ramsay in Scotland.

Argon became the first member of the noble gases to be discovered.

In 1957, IUPAC agreed that the symbol should change from A to Ar.
Elektron per kulit
2, 8, 8
Konfigurasi elektron
[Ne] 3s2 3p6
Ar
Argon makes a distinctive blue-green gas laser
Sifat Fisika
Fase
Gas
Kepadatan
0,0017837 g/cm3
Titik lebur
83,8 K | -189,35 °C | -308,83 °F
Titik didih
87,3 K | -185,85 °C | -302,53 °F
Kalor peleburan
1,18 kJ/mol
Kalor penguapan
6,5 kJ/mol
Kapasitas kalor molar
0,52 J/g·K
Kelimpahan di kerak bumi
0,00015%
Kelimpahan di alam semesta
0,02%
Vial
Kredit Gambar: Images-of-elements
Vial of glowing ultrapure argon
Nomor CAS
7440-37-1
PubChem CID Number
23968
Sifat Atom
Jari-jari atom
71 pm
Jari-jari kovalen
106 pm
Elektronegativitas
-
Potensi Ionisasi
15,7596 eV
Volume atom
22,4 cm3/mol
Kondusivitas termal
0,0001772 W/cm·K
Bilangan oksidasi
0
Aplikasi
Argon gas is used to fill conventional incandescent and fluorescent light bulbs.

Argon is also used as an inert gas shield for arc welding and cutting, as blanket for the production of titanium and other reactive elements.

It is used as a protective atmosphere for growing silicon and germanium crystals.
Argon is considered to be non-toxic
Isotop
Isotop stabil
36Ar, 38Ar, 40Ar
Isotop tidak stabil
30Ar, 31Ar, 32Ar, 33Ar, 34Ar, 35Ar, 37Ar, 39Ar, 41Ar, 42Ar, 43Ar, 44Ar, 45Ar, 46Ar, 47Ar, 48Ar, 49Ar, 50Ar, 51Ar, 52Ar, 53Ar