Template:Infobox barium

Barium, ₅₆Ba
Barium
Pronunciation	/ˈbɛəriəm/ (BAIR-ee-əm)
Appearance	sillery gray; wi a fauch yellae tint
Standard atomic weight Ar, std(Ba)	137.327(7)
Barium in the periodic cairt
	caesium ← barium → lanthanum
Atomic nummer (Z)	56
Group	group 2 (alkaline yird metals)
Period	period 6
Block	s-block
Element category	Alkaline earth metal
Electron confeeguration	[Xe] 6s2
Electrons per shell	2, 8, 18, 18, 8, 2
Pheesical properties
Phase at STP	solit
Meltin pynt	1000 K (727 °C, 1341 °F)
Bylin pynt	2118 K (1845 °C, 3353 °F)
Density (near r.t.)	3.51 g/cm3
when liquid (at m.p.)	3.338 g/cm3
Heat o fusion	7.12 kJ/mol
Heat o vapourisation	142 kJ/mol
Molar heat capacity	28.07 J/(mol·K)
Atomic properties
Oxidation states	+1, +2 strangly basic
Electronegativity	Pauling scale: 0.89
Ionisation energies	1st: 502.9 kJ/mol ; 2nd: 965.2 kJ/mol ; 3rd: 3600 kJ/mol ; ;
Atomic radius	empirical: 222 pm
Covalent radius	215±11 pm
Van der Waals radius	268 pm
	Colour lines in a spectral rangeSpectral lines o barium
Ither properties
Naitural occurrence	primordial
Creestal structur	body-centred cubic (bcc)
Speed o soond thin rod	1620 m/s (at 20 °C)
Thermal expansion	20.6 µm/(m·K) (at 25 °C)
Thermal conductivity	18.4 W/(m·K)
Electrical resistivity	332 nΩ·m (at 20 °C)
Magnetic orderin	paramagnetic
Young's modulus	13 GPa
Shear modulus	4.9 GPa
Bulk modulus	9.6 GPa
Mohs haurdness	1.25
CAS Nummer	7440-39-3
History
Diskivery	Carl Wilhelm Scheele (1772)
First isolation	Humphry Davy (1808)
Main isotopes o barium
	Decay modes in parentheses is predictit, but hisnae yet been observed
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style="text-align:left"\| data m.p. cat v
	in	calc from C	diff	report	ref
C	727	—	—
K	1000	1000	0
F	1341	1341	0
WD	727 !727 Celsius
input	C: 727, K: 1000, F: 1341
comment

style="text-align:left"\| data b.p. cat v
	in	calc from C	diff	report	ref
C	1845	—	—
K	2118	2118	0
F	3353	3353	0
WD	1897 !1897 Celsius
input	C: 1845, K: 2118, F: 3353
comment

References

↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. p. 112. ISBN 0080379419.
↑ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
↑ Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

[1] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. p. 112. ISBN 0080379419.

[CIAAW2013-2] Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.

[3] Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.

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