GOLD CHARACTERISTICS

  • Density: 19.30 g·cm−3 [in g·cm−3 – water is 1, Pb is 11.3, Os 22.6]
  • Colour: yellow (copper and cesium are the only other coloured metallic elements)
  • Total all-time production worldwide: 161,000 tonnes by 2009
  • Physical properties: most malleable and ductile of metals, unaffected by air, water or most corrosive compounds
  • Dissolves with aqua regia, cyanide and mercury
  • Conversion: 31.01 tonnes equals 1 Moz.
  • Modern uses: jewellery, dental, electronics, computers, bars, coins
  • Monetary use: hard asset to support paper currency
  • Recyling: most of the gold ever mined is still in use
  • Earliest mining: alluvial mining in middle-east and Africa several thousand years ago
  • Price in $US: $250 to $1400 since 1995. Pegged to US dollar at $35 before 1980s.
  • Price in terms of labour: one ounce of gold has been worth approximately one to two weeks labour [has remained in this bracket for centuries]
  • Minerals with essential gold: gold [Au], maldonite [AuBi], calaverite [AuTe], other tellurides, aurostibite, rhodite, uytenbogaardtite Ag3AuS2, fischesserite (Ag3AuSe2), auricupride, petrovskaite AuAgS
  • Melting point: 1064 °C
  • Boiling point: 2856 °C
  • Naturally-occurring isotope: Au197 only (rest have half lives of less than one year).
  • Atomic weight: 79
  • Atomic mass: 197.0
  • Periodic table column: below Cu and Ag
  • Periodic table row: after Os, Ir, Pt; before Hg, Tl, Pb, Bi
  • Similar elements: include Ag, Cu, PGEs, Bi depending upon chemical environment.
  • Oxidation states: -1, 1, 2, 3, 4, 5. Note +1 and +3
  • Electronegativity: 2.54 Pauling scale
  • Electron configuration: [Xe] 4f14 5d10 6s1
  • Ionisation energy: 1st 890.1 kJ.mol-1, 2nd 1980 kJ.mol-1
  • Atomic radius 144 pm
  • Covalent radius 136 +/-6 pm
  • Au1+ 137 pm, very large
  • Au3+ 85 pm
  • Co-ordination chemistry: linear (Au1+), square planar (Au3+)
  • Why is gold yellow?: Gold absorbs blue light to transfer an electron between its 5d and 6s orbitals. The 6s is unexpectedly low energy due to relativistic effects of this heavy element.

Leave a Reply

Your email address will not be published.