barium

• Description
• General information
• Physical data
• Radii
• Electronegativities
• Solid state structure
• Temperatures
• Enthalpies
• Ionization Enthalpies
• Isotopes
• Further information

Description

Barium is a metallic element, soft, and when pure is silvery white like lead. The metal oxidises very easily. It is decomposed by water or alcohol. Barium is one of the alkaline-earth metals. Small amounts of barium compounds are used in paints and glasses.

General information

Discoveror: Sir Humphrey Davy
Date discovered: 1808
Discovered at: England
Meaning of name: From the Greek word "barys" meaning "heavy"

Physical data

Standard state: solid at 298 K
Colour: silvery white
Density of solid at ambient temperature/kg m^-3: 3510
Molar volume/cm³: 38.16

Radii /pm

Atomic: 253
Covalent (single bond):
Pauling radius for the ion [Ba]^-: no data

Valence shell orbital radius maxima (R_max)

orbital	s	p	d	f
radius	235.4	no data	no data	no data

Electronegativities

Both values are quoted on the Pauling scale.

Pauling: 0.89
Allred Rochow: 0.97

Crystal Structure

structure: bcc (body-centred cubic)

The following CrystalMaker image represents the solid state structure. For most elements, the most stable allotrope is illustrated. Try WebElements version 2 for interactive virtual reality and CHIME images.

Temperatures (/K)

melting point: 1000
boiling point: 2143

Enthalpies /kJ mol^-1

fusion: 8.0
vaporization: 140.2

single bond enthalpies:

Ba-F	Ba-Cl	Ba-Br	Ba-I	Ba-Ba
578	475	427	360	no data

Ionization enthalpies /kJ mol^-1

Number	Enthalpy
1st	502.9
2nd	965.3

Isotopes

This section gives some data for naturally occurring isotopes.

Nominal mass	Accurate mass	% natural abundance
130Ba	129.906282 (8)	0.106 (2)
132Ba	131.905042 (9)	0.101 (2)
134Ba	133.904486 (7)	2.417 (27)
135Ba	134.90566597)	6.592 (18)
136Ba	135.904553 (7)	7.854 (39)
137Ba	136.905812 (6)	11.23 (4)
138Ba	137.905232 (6)	71.70 (7)

Further Information

• Additional information about WebElements 1.2.2
• This is a licensed copy (here is the full list) of WebElements 1.2.2 and contains a subset of the material contained within the main version of WebElements (version 2)
• For further information please try WebElements version 2
• Sheffield Chemdex: perhaps the largest internet chemistry directory
• Sheffield Chemputer: interactive chemistry calculators on the WWW