Barium

56
Ba
Gruppe
2
Periode
6
Blok
s
Protoner
Elektroner
Neutroner
56
56
81
Generelle Egenskaber
Atomnummer
56
Atommasse
137,327
Masseantal
137
Kategori
Jordalkalimetaller
Farve
Sølv
Radioaktiv
Nej
From the Greek word barys, heavy
Krystalstruktur
Rumcentreret Kubisk
Historie
Barium was identified as a new element in 1774 by Carl Wilhelm Scheele.

Barium was first isolated by electrolysis of molten barium salts in 1808, by Sir Humphry Davy in England.

Robert Bunsen and Augustus Matthiessen obtained pure barium by electrolysis of a molten mixture of barium chloride and ammonium chloride.
Elektroner i hver skal
2, 8, 18, 18, 8, 2
Elektronkonfiguration
[Xe] 6s2
Ba
At low doses, barium acts as a muscle stimulant
Fysiske Egenskaber
Tilstandsform
Fast stof
Massefylde
3,594 g/cm3
Smeltepunkt
1000,15 K | 727 °C | 1340,6 °F
Kogepunkt
2170,15 K | 1897 °C | 3446,6 °F
Smeltevarme
8 kJ/mol
Fordampningsvarme
140 kJ/mol
Varmefylde
0,204 J/g·K
Forekomst i jordskorpen
0,034%
Forekomst i universet
1×10-6%
Barium
Billede akkrediteringer: Images-of-elements
Barium with a grey oxide layer under argon
CAS-nummer
7440-39-3
PubChem CID-nummer
5355457
Atomare egenskaber
Atomradius
222 pm
Kovalent radius
215 pm
Elektronegativitet
0,89 (Paulings skala)
Ioniseringspotentiale
5,2117 eV
Atomvolumen
39,24 cm3/mol
Varmeledningsevne
0,184 W/cm·K
Oxidationstrin
2
Anvendelser
Barium is used as a flashed getter in vacuum tubes to remove the last traces of gases.

It is often used in barium-nickel alloys for spark plug wire.

Barium sulfate is important to the petroleum industry as a drilling fluid in oil and gas wells.

Barium is also used in medicine to detect abnormalities in the digestive system.
Water-soluble barium compounds are poisonous
Isotoper
Stabile isotoper
130Ba, 132Ba, 134Ba, 135Ba, 136Ba, 137Ba, 138Ba
Ustabile isotoper
114Ba, 115Ba, 116Ba, 117Ba, 118Ba, 119Ba, 120Ba, 121Ba, 122Ba, 123Ba, 124Ba, 125Ba, 126Ba, 127Ba, 128Ba, 129Ba, 131Ba, 133Ba, 139Ba, 140Ba, 141Ba, 142Ba, 143Ba, 144Ba, 145Ba, 146Ba, 147Ba, 148Ba, 149Ba, 150Ba, 151Ba, 152Ba, 153Ba