10 Interesting Facts About Gallium
Gallium is an element of the main subgroup of the third group of the fourth period of Mendeleev’s periodic table of chemical elements, with atomic number 31. It is denoted by the symbol Ga (Latin: Gallium). It belongs to the group of light metals. The simple substance gallium (CAS number: 7440-55-3) is a soft ductile metal with a silvery-white color with a bluish tint. By the way, gallium is a metal that melts in your hands.
1. The existence of gallium was scientifically predicted by D. I. Mendeleev. When creating the periodic table of chemical elements in 1869, based on the Periodic Law discovered by him, he left vacancies in the third group for unknown elements – analogues of aluminum and silicon (ekaaluminium and eqasilicium). Mendeleev, based on the properties of neighboring, well-studied elements, quite accurately described not only the most important physical and chemical properties, but also the method of discovery – spectroscopy. In particular, in an article dated December 11 (November 29, old style) 1870, published in the Journal of the Russian Chemical Society. Mendeleev pointed out that the atomic weight of aluminum is close to 68, with a specific gravity of about 6 g/cm3. In the metallic state, the metal will be fusible. Gallium was soon discovered, isolated as a simple substance, and studied by the French chemist Paul Émile Lecoq de Boisbaudrand. September 20, 1875. At a meeting of the Paris Academy of Sciences, a letter from Lecoq de Boisbaudran on the discovery of a new element and the study of its properties was read. The letter reported that on August 27, 1875, between 3 and 4 p.m., he found signs of a new simple body in a sample of zinc blende brought from the Pierfitte mine in the Argeles Valley (Pyrenees). For example, while studying the spectrum of the sample, Lecoq de Boisbaudran identified two new purple lines indicating the presence of an unknown element in the mineral. In the same letter, he suggested naming the new element Gallium. Isolation of the element was fraught with considerable difficulties, since the content of the new element in the ore was less than 0.2%. As a result, Lecoq de Boisbaudran managed to obtain a new element in an amount of less than 0.1 g and study it. In terms of properties, the new element turned out to be similar to zinc.
2. Paul Émile Lecoq de Boisbaudran named the element in honor of his homeland, France, after its Latin name – Gallia. Although there is an undocumented legend that in the name of the element, its discoverer implicitly immortalized his surname (Lecoq). The Latin name of the element (Gallium) is consonant with gallus – “rooster” (Latin). It is noteworthy that it is the rooster le coq (French) that is the symbol of France.
3. The density of gallium in the solid state at a temperature of 20°C is 5.904 g/cm³, liquid gallium (tpl. = 29.8°C) has a density of 6.095 g/cm³, that is, when solidified, the volume of gallium increases. This property is very rare, exhibited only by a few simple substances and compounds (in particular, water, silicon, germanium, antimony, bismuth and plutonium).
4. At low temperatures, it is in a solid state, but melts at a temperature not much higher than room temperature (29.8°C).
5. Gallium boils at 2230°C. One of the features of gallium is a wide temperature range of the liquid state (from 30 to 2230°C), while it has a low vapor pressure at temperatures up to 1100-1200°C.
6. The specific heat capacity of solid gallium in the temperature range T = 0-24°C is equal to 376.7 J/kg•K (0.09 cal/g•deg.), in the liquid state at T = 29-100°C, the specific heat capacity is 410 J/kg•K (0.098 cal/g•deg).
Gallium is mined mainly from zinc ores and bauxite, it does not exist in its pure form.
7. The average content of gallium in the earth’s crust is 19 g/t.
8. The main deposits of gallium are located in South-West Africa, Russia, and the CIS countries.
9. At present, gallium is mainly used in microelectronics.
10. It is widely used in medicine, as it has been found that gallium particles are able to replace iron particles necessary for the functioning of the body. It is also included in the composition of various medicines. Metallic gallium, among other things, fills quartz thermometers for measuring high temperatures, replacing the mercury we are used to. This is due to the fact that, compared to mercury, the metal has a very high boiling point.