 |
Introduction:
Gold is located in Group IB of the periodic table with a
symbol of Au.
Atomic Number: 79
Atomic Weight: 196.96654 amu
Density: Ranges from 19.2 to
19.4 g/cm3
(1210 lb/ft3).
Melting Point: 1064.18° C (1337.5801 K, 1947.9741 °F)
Boiling Point: 2856° C (3080.15 K, 5084.6 °F)
Number of Protons/Electrons: 79
Number of Neutrons: 118
Crystal Structure: Cubic
Classification: Transition Metal
Structure:
Gold crystals are face-centered cubic but can also be
octahedral or dodecahedral.
There is only one known naturally occurring isotope of gold
known as 197Au. 19 isotopes have been produced in
a laboratory ranging in mass number from 185Au to
203Au. All of these artificially produced
isotopes are radioactive and contain a wide range of half
lives ranging from a few seconds to 186 days.
Pure gold is not magnetic however gold mixed with manganese
is partially magnetic, and some alloys of gold with iron,
nickel, and cobalt are ferromagnetic.
Gold is the most inert of the metallic elements and is
highly stable and resistant to corrosion. It is a good
conductor of electricity as well as heat and also is the
most ductile and malleable of the metals.
Gold is resistant to attack by most simple mineral acids
excluding selenic acid. It may be dissolved in hydrochloric
acid when an oxidizing material is present. Gold can also be
dissolved by dry or aqueous chlorination as well as alkaline
cyanide solution in the presence of oxygen. Gold is
resistant to attack by hydrogen, nitrogen, selenium and
oxygen. Gold however reacts to Tellurium to form
intermetallic compounds. The addition of high amounts of
silver or other metallic impurities such as copper, iron or
nickel will increase gold’s corrosion susceptibility.
Popular Abbreviations:
There are several different abbreviations for Karat that
should be known. The following table demonstrates the most
common of them:
|
Abbreviation |
Meaning |
|
YG or KY |
Yellow Gold |
|
WG or KW |
White Gold |
|
K or KT |
Karat |
|
 |
