Gold

Gold (Au)

Gold is gold colored. It is the most malleable and ductile metal known. There is only one stable isotope of gold, and five radioisotopes of gold, Au-195 being the most stable with a half-life of 186 days. Gold is used as a monetary standard, in jewelry, dentistry, electronics. Au-198 is used in treating cancer and some other medical conditions. Gold has been known to exist as far back as 2600 BC. Gold comes from the Anglo-Saxon word gold. Its symbol, Au, comes from the Latin word aurum, which means gold. Gold is not particularly toxic, however it is known to cause damage to the liver and kidneys in some.
Atomic Number79
Atomic Weight196.966569
Mass Number197
Group11
Period6
Blockd
Protons79 p+
Neutrons118 n0
Electrons79 e-
Gold-crystals.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
135 pm
Atomic Volume
Covalent Radius
124 pm
Metallic Radius
134 pm
Ionic Radius
137 pm
Crystal Radius
151 pm
Van der Waals radius
214 pm
Density
19.3 g/cm³
Boiling Point
3,080 K
Melting Point
1,337.58 K
Electrons per shell2, 8, 18, 32, 18, 1
Electronegativity
2.4
Electrophilicity
2.4042008541495 eV/particle
Proton Affinity
Electron Affinity
2.30863 eV/particle
Ionization Potential
9.225553 eV/particle
Heat of Vaporization
340 kJ/mol
Heat of Fusion
12.68 kJ/mol
Heat of Formation
368.2 kJ/mol
Molar Heat Capacity
25.418 J/(mol K)
Specific Heat Capacity
0.129 J/(g⋅K)
Thermal Conductivity
Gas Basicity
Dipole Polarizability
36 a₀
C6 Dispersion Coefficient
Oxidation States-1, 1, 2, 3, 5
Color
Gold
Crystal StructureFace Centered Cubic (FCC)
Lattice Constant
4.08 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Xe] 4f14 5d10 6s1
Magnetic Ordering
Magnetic Susceptibility
PhaseSolid
Poisson Ratio
Shear Modulus
Young's Modulus
Allotropes
Alternate Names
Adiabatic Index
Appearance
Electric Conductivity
Critical Pressure
Critical Temperature
Curie Point
Electrical
Hardness
Magnetic Susceptibility
Magnetic
Neel Point
Neutron Cross Section
Neutron Mass Absorption
Gas Phase
Quantum Numbers
Refractive Index
Space Group
Speed of Sound
Superconducting Point
Thermal Expansion
Valence Electrons
Classification
CategoryTransition metals, Transition metals
CAS GroupIB
IUPAC GroupIB
Glawe Number66
Mendeleev Number73
Pettifor Number70
Geochemical Classnoble metal
Goldschmidt Classsiderophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
0.004 mg/kg
Abundance in Oceans
0.000004 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe6×10-8%

Isotopes of Gold

Stable Isotopes
197Au
Unstable Isotopes
169Au 170Au 171Au 172Au 173Au 174Au 175Au 176Au 177Au 178Au 179Au 180Au 181Au 182Au 183Au 184Au 185Au 186Au 187Au 188Au 189Au 190Au 191Au 192Au 193Au 194Au 195Au 196Au 198Au 199Au 200Au 201Au 202Au 203Au 204Au 205Au

History

Gold has been known since prehistoric times and was the first metal used by humans. Gold artifacts dated to 5000 years ago have been found in Egyptian tombs. Gold of 98% purity has been found in Nahal Qunah in the ancient kingdom of Israel, dating from about 6000 years ago. From the Latin word aurum meaning gold

DiscoverersKnown to the ancients.
Discovery Location
Discovery Year
Name OriginAnglo-Saxon: geolo (yellow); symbol from Latin: aurum (shining dawn).
Gold is considered to be non-toxic
India is the world's largest single consumer of gold

Uses

Gold is used in coinage and is a standard for monetary systems in many countries. It is also extensively used for jewelry, decoration, dental work, and for plating. Gold is used widely in microelectronic circuits to ensure reliable, corrosion-resistant and static-free performance. Gold leaf, flake or dust is used in some gourmet foods as decorative ingredient. Very malleable. Used in electronics, jewelry and coins. It is a good reflector of infrared radiation, so a thin film of gold is applied to the glass of skyscrapers to reduce internal heating from sunlight.

Sources

Found in veins in the crust, with cooper ore and native .