Gallium

Gallium (Ga)

Soft silvery metallic element, belongs to group 13 of the periodic table. The two stable isotopes are Ga-69 and Ga-71. Eight radioactive isotopes are known, all having short half-lives. Gallium Arsenide is used as a semiconductor. Corrodes most other metals by diffusing into their lattice. First identified by Francois Lecoq de Boisbaudran in 1875.
Atomic Number31
Atomic Weight69.723
Mass Number69
Group13
Period4
Blockp
Protons31 p+
Neutrons38 n0
Electrons31 e-
Gallium crystals.jpg Animated Bohr Model Enhanced Bohr Model Bohr Model Orbital Diagram

Properties

Atomic Radius
130 pm
Atomic Volume
Covalent Radius
124 pm
Metallic Radius
125 pm
Ionic Radius
47 pm
Crystal Radius
61 pm
Van der Waals radius
187 pm
Density
5.91 g/cm³
Boiling Point
2,676 K
Melting Point
302.93 K
Electrons per shell2, 8, 18, 3
Electronegativity
1.81
Electrophilicity
0.9277626514037 eV/particle
Proton Affinity
Electron Affinity
Ionization Potential
5.9993018 eV/particle
Heat of Vaporization
270.3 kJ/mol
Heat of Fusion
5.59 kJ/mol
Heat of Formation
271.96 kJ/mol
Molar Heat Capacity
26.03 J/(mol K)
Specific Heat Capacity
0.373 J/(g⋅K)
Thermal Conductivity
28.1 W/(m K)
Gas Basicity
Dipole Polarizability
50 a₀
C6 Dispersion Coefficient
498 a₀
Oxidation States1, 2, 3
Color
Silver
Crystal StructureBase Centered Orthorhombic (ORC)
Lattice Constant
4.51 Å
Bulk Modulus
Electrical Resistivity
Electron Configuration[Ar] 3d10 4s2 4p1
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
CategoryPost-transition metals, Poor metals
CAS GroupIIIB
IUPAC GroupIIIA
Glawe Number79
Mendeleev Number83
Pettifor Number81
Geochemical Class
Goldschmidt Classchalcophile
Radioactivity
RadioactiveNo
Decay Mode
Half-Life
Lifetime
Abundance
Abundance in Earth's crust
Abundance in Oceans
0.00003 mg/L
Abundance in Human Body
Abundance in Meteor
Abundance in Sun
Abundance in Universe1×10-6%

Isotopes of Gallium

Stable Isotopes
69Ga 71Ga
Unstable Isotopes
56Ga 57Ga 58Ga 59Ga 60Ga 61Ga 62Ga 63Ga 64Ga 65Ga 66Ga 67Ga 68Ga 70Ga 72Ga 73Ga 74Ga 75Ga 76Ga 77Ga 78Ga 79Ga 80Ga 81Ga 82Ga 83Ga 84Ga 85Ga 86Ga

History

In 1871, existence of gallium was first predicted by Russian chemist Dmitri Mendeleev and called the element eka-aluminum. Gallium was discovered spectroscopically by French chemist Paul Emile Lecoq de Boisbaudran in 1875 by its characteristic spectrum in an examination of a sphalerite sample. Later that year, Lecoq obtained the free metal by electrolysis of its hydroxide in potassium hydroxide solution. From the Latin word Gallia, France; also from Latin, gallus, a translation of Lecoq, a cock

DiscoverersPaul Émile Lecoq de Boisbaudran
Discovery LocationFrance
Discovery Year1875
Name OriginLatin: Gallia (France).
Gallium is considered to be non-toxic
Gallium has a strong tendency to supercool below its melting point / freezing point

Uses

Gallium wets glass or porcelain and forms a brilliant mirror when it is painted on glass. It is widely used in doping semiconductors and producing solid-state devices such as transistors. Low melting gallium alloys are used in some medical thermometers as non-toxic substitutes for mercury. Gallium arsenide is capable of converting electricity directly into coherent light. Used in semiconductor production. It us used in making LEDs (light-emitting diodes) and GaAs laser diodes.

Sources

Found throughout the crust in minerals like bauxite, germanite and coal.