Gallium has similarities to the other metals of the group, aluminium, indium, and thallium. Gallium does not occur as a free element in nature, but as gallium(III) compounds in trace amounts in zinc ores and in bauxite. Gallium consumption is centred on the superconductor industry. Gallium is mainly recovered as a by-product of treating bauxite (the main source of aluminium).
Protons and Neutrons in Gallium
Gallium is a chemical element with atomic number 31 which means there are 31 protons in its nucleus. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs.
The total number of neutrons in the nucleus of an atom is called the neutron number of the atom and is given the symbol N. Neutron number plus atomic number equals atomic mass number: N+Z=A. The difference between the neutron number and the atomic number is known as the neutron excess: D = N – Z = A – 2Z.
For stable elements, there is usually a variety of stable isotopes. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. Mass numbers of typical isotopes of Gallium are 69; 71.
Main Isotopes of Gallium
Only two isotopes are stable and occur naturally, gallium-69 and gallium-71. Gallium-69 is more abundant: it makes up about 60.1% of natural gallium, while gallium-71 makes up the remaining 39.9%.
Gallium-69 is composed of 31 protons, 38 neutrons, and 31 electrons.
Gallium-71 is composed of 31 protons, 40 neutrons, and 31 electrons.
Gallium-67 (half-life 3.3 days) is a gamma-emitting isotope (the gamma emitted immediately after electron-capture) used in standard nuclear medical imaging, in procedures usually referred to as gallium scans.
Electrons and Electron Configuration
The number of electrons in an electrically-neutral atom is the same as the number of protons in the nucleus. Therefore, the number of electrons in neutral atom of Gallium is 31. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z – 1) negative electrons in the atom.
Since the number of electrons and their arrangement are responsible for the chemical behavior of atoms, the atomic number identifies the various chemical elements. The configuration of these electrons follows from the principles of quantum mechanics. The number of electrons in each element’s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. In the periodic table, the elements are listed in order of increasing atomic number Z.
Electron configuration of Gallium is [Ar] 3d10 4s2 4p1.
Possible oxidation states are +3.
Gallium is found primarily in the +3 oxidation state. The +1 oxidation state is also found in some compounds, although it is less common than it is for gallium’s heavier congeners indium and thallium.
Most Common Alloy of Gallium
Galinstan is a eutectic alloy composed of gallium, indium, and tin (hence its name, which is derived from the gallium, indium, and stannum, the Latin name for tin). Galistan melts at −19 °C (−2 °F) and is thus liquid at room temperature. Due to the low toxicity and low reactivity of its component metals, in many applications, galinstan has replaced the toxic liquid mercury or the reactive NaK (sodium–potassium alloy). Metals or alloys like galinstan that are liquids at room temperature are often used by overclockers and enthusiasts as a thermal interface for computer hardware cooling, where their higher thermal conductivity compared to thermal pastes and thermal epoxys can allow slightly higher clock speeds and CPU processing power achieved in demonstrations and competitive overclocking.
|Number of protons||31|
|Number of neutrons (typical isotopes)||69; 71|
|Number of electrons||31|
|Electron configuration||[Ar] 3d10 4s2 4p1|
Properties of other elements