Gallium Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Gallium is a chemical element with symbol Ga and atomic number 31. Elemental gallium does not occur in free form in nature, but as the gallium(III) compounds that are in trace amounts in zinc ores and in bauxite. Gallium is a soft, silvery metal, and elemental gallium is a brittle solid at low temperatures, and melts at 29.76 °C (85.57 °F) (slightly above room temperature).
It belongs to group 13 of the periodic table having trivial name triels, icosagens. You can also download Printable Periodic Table of Elements Flashcards for Gallium in a PDF format.
Gallium Facts
Read key information and facts about element Gallium
| Name | Gallium |
| Atomic Number | 31 |
| Atomic Symbol | Ga |
| Atomic Weight | 69.723 |
| Phase | Solid |
| Color | Silver |
| Appearance | silver-white |
| Classification | Post Transition Metal |
| Natural Occurance | Primordial |
| Group in Periodic Table | 13 |
| Group Name | boron family |
| Period in Periodic Table | period 4 |
| Block in Periodic Table | p-block |
| Electronic Configuration | [Ar] 3d10 4s2 4p1 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 3 |
| Melting Point | 302.91 K |
| Boiling Point | 2477 K |
| CAS Number | CAS7440-55-3 |
How to Locate Gallium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 31 to find Gallium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Gallium on periodic table look for cross section of group 13 and period 4 in the modern periodic table.
Gallium History
The element Gallium was discovered by P. E. L. de Boisbaudran in year 1875 in France. Gallium was first isolated by P. E. L. de Boisbaudran in . Gallium derived its name from Gallia, the Latin name for France.
| Discovered By | P. E. L. de Boisbaudran |
| Discovery Date | 1875 in France |
| First Isolation | |
| Isolated by | P. E. L. de Boisbaudran |
Boisbaudran observed on a pyrenea blende sample some emission lines corresponding to the eka-aluminium that waspredictedby Mendeleev in 1871 and subsequently isolated the element by electrolysis.
Gallium Uses
As gallium has a low melting point, it is often used in medical thermometers as a substitute for mercury. It is used in semiconductors, lasers, and solar panels when combined with arsenic. It can also be used in mirror manufacturing.
Gallium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Gallium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
| ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
|---|---|---|
| Abundance in Universe | 10 | 0.2 |
| Abundance in Sun | 40 | 0.6 |
| Abundance in Meteorites | 7800 | 2000 |
| Abundance in Earth's Crust | 19000 | 5500 |
| Abundance in Oceans | 0.03 | 0.0027 |
| Abundance in Humans | - | - |
Crystal Structure of Gallium
The solid state structure of Gallium is Base Centered Orthorhombic.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
| a | b | c |
|---|---|---|
| 451.97 pm | 766.33 pm | 452.6 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
| alpha | beta | gamma |
|---|---|---|
| π/2 | π/2 | π/2 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
| Space Group Name | Cmca |
| Space Group Number | 64 |
| Crystal Structure | Base Centered Orthorhombic |
| Number of atoms per unit cell | 2 |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Gallium Atomic and Orbital Properties
Gallium atoms have 31 electrons and the electronic shell structure is [2, 8, 18, 3] with Atomic Term Symbol (Quantum Numbers) 2P1/2.
| Atomic Number | 31 |
| Number of Electrons (with no charge) | 31 |
| Number of Protons | 31 |
| Mass Number | 70 |
| Number of Neutrons | 39 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 3 |
| Electron Configuration | [Ar] 3d10 4s2 4p1 |
| Valence Electrons | 4s2 4p1 |
| Valence (Valency) | 3 |
| Main Oxidation States | 3 |
| Oxidation States | -5, -4, -3, -2, -1, 0, 1, 2, 3 |
| Atomic Term Symbol (Quantum Numbers) | 2P1/2 |
Bohr Atomic Model of Gallium - Electrons per energy level
| n | s | p | d | f |
|---|
Ground State Electronic Configuration of Gallium - neutral Gallium atom
Abbreviated electronic configuration of Gallium
The ground state abbreviated electronic configuration of Neutral Gallium atom is [Ar] 3d10 4s2 4p1. The portion of Gallium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Ar]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4s2 4p1, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Gallium
Complete ground state electronic configuration for the Gallium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p1
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
Atomic Structure of Gallium
Gallium atomic radius is 136 pm, while it's covalent radius is 126 pm.
| Atomic Radius Calculated | 136 pm(1.36 Å) |
| Atomic Radius Empirical | 130 pm (1.3 Å) |
| Atomic Volume | 11.809 cm3/mol |
| Covalent Radius | 126 pm (1.26 Å) |
| Van der Waals Radius | 187 pm |
| Neutron Cross Section | 2.9 |
| Neutron Mass Absorption | 0.0015 |
Spectral Lines of Gallium - Atomic Spectrum of Gallium
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.
Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.
Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.
Emission spectrum of Gallium
Absorption spectrum of Gallium
Gallium Chemical Properties: Gallium Ionization Energies and electron affinity
The electron affinity of Gallium is 28.9 kJ/mol.
| Valence | 3 |
| Electronegativity | 1.81 |
| ElectronAffinity | 28.9 kJ/mol |
Ionization Energy of Gallium
Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).
Refer to table below for Ionization energies of Gallium
| Ionization energy number | Enthalpy - kJ/mol |
|---|---|
| 1st | 578.8 |
| 2nd | 1979.3 |
| 3rd | 2963 |
| 4th | 6180 |
Gallium Physical Properties
Refer to below table for Gallium Physical Properties
| Density | 5.904 g/cm3(when liquid at m.p density is $6.095 g/cm3) |
| Molar Volume | 11.809 cm3/mol |
Elastic Properties
| Young Modulus | - |
| Shear Modulus | - |
| Bulk Modulus | - |
| Poisson Ratio | - |
Hardness of Gallium - Tests to Measure of Hardness of Element
| Mohs Hardness | 1.5 MPa |
| Vickers Hardness | - |
| Brinell Hardness | 60 MPa |
Gallium Electrical Properties
Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).
Gallium is a conductor of electricity. Refer to table below for the Electrical properties of Gallium
| Electrical conductors | Conductor |
| Electrical Conductivity | 7100000 S/m |
| Resistivity | 1.39e-7 m Ω |
| Superconducting Point | 1.083 |
Gallium Heat and Conduction Properties
| Thermal Conductivity | 29 W/(m K) |
| Thermal Expansion | 0.00012 /K |
Gallium Magnetic Properties
| Magnetic Type | Diamagnetic |
| Curie Point | - |
| Mass Magnetic Susceptibility | -3e-9 m3/kg |
| Molar Magnetic Susceptibility | -2.09e-10 m3/mol |
| Volume Magnetic Susceptibility | -0.0000177 |
Optical Properties of Gallium
| Refractive Index | - |
Acoustic Properties of Gallium
| Speed of Sound | 2740 m/s |
Gallium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Gallium
| Melting Point | 302.91 K(29.76 °C, 85.568 °F) |
| Boiling Point | 2477 K(2203.85 °C, 3998.930 °F) |
| Critical Temperature | - |
| Superconducting Point | 1.083 |
Enthalpies of Gallium
| Heat of Fusion | 5.59 kJ/mol |
| Heat of Vaporization | 256 kJ/mol |
| Heat of Combustion | - |
Gallium Isotopes - Nuclear Properties of Gallium
Gallium has 31 isotopes, with between 56 and 86 nucleons. Gallium has 2 stable naturally occuring isotopes.
Isotopes of Gallium - Naturally occurring stable Isotopes: 69Ga, 71Ga.
| Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
|---|---|---|---|---|---|---|
| 56Ga | 31 | 25 | 56 | Synthetic | ||
| 57Ga | 31 | 26 | 57 | Synthetic | ||
| 58Ga | 31 | 27 | 58 | Synthetic | ||
| 59Ga | 31 | 28 | 59 | Synthetic | ||
| 60Ga | 31 | 29 | 60 | Synthetic | ||
| 61Ga | 31 | 30 | 61 | Synthetic | ||
| 62Ga | 31 | 31 | 62 | Synthetic | ||
| 63Ga | 31 | 32 | 63 | Synthetic | ||
| 64Ga | 31 | 33 | 64 | Synthetic | ||
| 65Ga | 31 | 34 | 65 | Synthetic | ||
| 66Ga | 31 | 35 | 66 | Synthetic | ||
| 67Ga | 31 | 36 | 67 | Synthetic | ||
| 68Ga | 31 | 37 | 68 | Synthetic | ||
| 69Ga | 31 | 38 | 69 | 60.108% | Stable | N/A |
| 70Ga | 31 | 39 | 70 | Synthetic | Stable | |
| 71Ga | 31 | 40 | 71 | 39.892% | Stable | N/A |
| 72Ga | 31 | 41 | 72 | Synthetic | ||
| 73Ga | 31 | 42 | 73 | Synthetic | ||
| 74Ga | 31 | 43 | 74 | Synthetic | ||
| 75Ga | 31 | 44 | 75 | Synthetic | ||
| 76Ga | 31 | 45 | 76 | Synthetic | ||
| 77Ga | 31 | 46 | 77 | Synthetic | ||
| 78Ga | 31 | 47 | 78 | Synthetic | ||
| 79Ga | 31 | 48 | 79 | Synthetic | ||
| 80Ga | 31 | 49 | 80 | Synthetic | ||
| 81Ga | 31 | 50 | 81 | Synthetic | ||
| 82Ga | 31 | 51 | 82 | Synthetic | ||
| 83Ga | 31 | 52 | 83 | Synthetic | ||
| 84Ga | 31 | 53 | 84 | Synthetic | ||
| 85Ga | 31 | 54 | 85 | Synthetic | ||
| 86Ga | 31 | 55 | 86 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.
NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.
The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.
| NFPA Fire Rating | 0 | Will not burn |
| NFPA Health Rating | 1 | Flash Points Above 93.3°C (200°F) |
| NFPA Reactivity Rating | 0 | Will not burn |
| NFPA Hazards |
| Autoignition Point | - |
| Flashpoint | - |
Database Search
List of unique identifiers to search the element in various chemical registry databases
| Database | Identifier number |
|---|---|
| CAS Number - Chemical Abstracts Service (CAS) | CAS7440-55-3 |
| RTECS Number | RTECSLW8600000 |
| CID Number | CID5360835 |
| Gmelin Number | - |
| NSC Number | - |
Compare Gallium with other elements
Compare Gallium with Group 13, Period 4 and Post Transition Metal elements of the periodic table.
Compare Gallium with all Group 13 elements
Compare Gallium with all Period 4 elements
Compare Gallium with all Post Transition Metal elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Gallium