Ang bulawan o oro (Iningles gold ) mao ang elementong kimiko sa talaang peryodiko nga may simbolo nga Au ug kaiphan nga atomik 79. Ang bulawan mao ang puthaw nga transisyon .
Quick Facts Gold, Panagway ...
Gold
79
Panagway
metallic yellow
Kinatibuk-ang mga kinaiya
Ngalan, simbolo , kaiphan
gold, Au, 79
Paglitok
Kategoriyang elemento puthaw nga transisyon
Group , period , block 11 , 6 , d
Gibug-aton sa atomo 196.966569(4)
Kontorno sa elektron [ Xe ] 4f14 5d10 6s1 Electron shells of gold (2, 8, 18, 32, 18, 1)
History
Pagkadiskobre Middle Easterns (before 6000 BC )
Physical properties
Phase magahi
Density (near r.t. )19.30 g·cm−3
Liquid density at m.p.
17.31 g·cm−3
Melting point 1337.33 K , 1064.18 °C, 1947.52 °F
Boiling point 3129 K, 2856 °C, 5173 °F
Heat of fusion 12.55 kJ·mol−1
Heat of vaporization 324 kJ·mol−1
Molar heat capacity 25.418 J·mol−1 ·K−1
Vapor pressure
P (Pa)
1
10
100
1 k
10 k
100 k
at T (K)
1646
1814
2021
2281
2620
3078
Atomic properties
Oxidation states 5, 4, 3 , 2, 1, −1, −2amphoteric oxide)
Electronegativity 2.54 (Pauling scale)
Ionization energies 1st: 890.1 kJ·mol−1
2nd: 1980 kJ·mol−1
Atomic radius 144 pm
Covalent radius 136±6 pm
Van der Waals radius 166 pm
Miscellanea
Crystal structure lattice face centered cubic
Magnetic ordering diamagnetic [ 1]
Electrical resistivity (20 °C) 22.14 nΩ·m
Thermal conductivity 318 W·m−1 ·K−1
Thermal expansion (25 °C) 14.2 µm·m−1 ·K−1
Speed of sound (thin rod)(r.t. ) 2030 m·s−1
Tensile strength 120 MPa
Young's modulus 79 GPa
Shear modulus 27 GPa
Bulk modulus 180 GPa
Poisson ratio 0.44
Mohs hardness 2.5
Vickers hardness 216 MPa
Brinell hardness 25 HB MPa
CAS registry number 7440-57-5
Most stable isotopes
Main article: Isotopes of gold
iso NA half-life DM DE (MeV ) DP
195 Ausyn 186.10 d
ε 0.227
195 Pt
196 Ausyn 6.183 d
ε 1.506
196 Pt
β− 0.686
196 Hg
197 Au100%
197 Au is stable with 118 neutrons
198 Ausyn 2.69517 d
β− 1.372
198 Hg
199 Ausyn 3.169 d
β− 0.453
199 Hg
· r
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