Barium, 56 Ba Barium Pípè / ˈ b ɛər i ə m / (BAIR -ee-əm ) Ìhànsójú silvery gray Ìwúwo átọ̀mù A r, std (Ba) 137.327(7) [ 1] Barium ní orí tábìlì àyè
Nọ́mbà átọ̀mù (Z ) 56 Ẹgbẹ́ group 2 (alkaline earth metals) Àyè àyè 6 Àdìpọ̀ Àdìpọ̀-s Ẹ̀ka ẹ́límẹ́ntì Alkaline earth metal Ìtò ẹ̀lẹ́ktrọ́nù [Xe ] 6s2 Iye ẹ̀lẹ́ktrọ́nù lórí ìpele kọ̀ọ̀kan 2, 8, 18, 18, 8, 2 Àwọn ohun ìní ara Ìfarahàn at STP solid Ìgbà ìyọ́ 1000 K (727 °C, 1341 °F) Ígbà ìhó 2170 K (1897 °C, 3447 °F) Kíki (near r.t. ) 3.51 g/cm3 when liquid (at m.p. ) 3.338 g/cm3 Heat of fusion 7.12 kJ/mol Heat of 140.3 kJ/mol Molar heat capacity 28.07 J/(mol·K) pressure
P (Pa)
1
10
100
1 k
10 k
100 k
at T (K)
911
1038
1185
1388
1686
2170
Atomic properties Oxidation states +1, +2 Àdàkọ:Infobox element/symbol-to-oxidation-state/comment Electronegativity Pauling scale: 0.89 Atomic radius empirical: 222 pm Covalent radius 215±11 pm Van der Waals radius 268 pm Color lines in a spectral range Spectral lines of bariumOther properties Natural occurrence primordial Crystal structure (bcc) Speed of sound 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 n Ω·m (at 20 °C) Magnetic ordering paramagnetic Young's modulus 13 GPa Shear modulus 4.9 GPa Bulk modulus 9.6 GPa Mohs hardness 1.25 CAS Number 7440-39-3 Main isotopes of barium
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↑ Meija, Juris; Coplen, Tyler B.; Berglund, Michael; Brand, Willi A.; De Bièvre, Paul; Gröning, Manfred; Holden, Norman E.; Irrgeher, Johanna 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 .