What Is Scandium?
Scandium is an element with the element symbol Sc and atomic number 21.
Scandium is a group 3 element, a rare earth element, and a transition element. It is a soft, silvery metal that forms a light yellow or light peach-colored passivity when oxidized in air. It is also characterized by its ability to react with halogen elements at room temperature.
Scandium is not a particularly rare element on earth. Its abundance is estimated to be 15-25 ppm, making it the 50th most abundant element. However, it is not present in concentrated amounts, but is found in small amounts in minerals.
Uses of Scandium
Scandium has not been widely applied to any element or compound state because of its high reactivity with halogen elements, as well as its high price. In recent years, however, it has been attracting attention as a new material.
The application that has attracted the most attention is its use in lighting. It has been reported that using scandium iodide (ScI3) in metal halide lamps produces more intense light. Other applications have also been found, such as adding Scandium to aluminum alloys and to the anode of nickel-alkali storage batteries to stabilize voltage and extend service life.
The main application of scandium by weight is in aluminum-scandium alloys, which are high-performance materials. In addition to some aerospace parts, it is used as a material for sporting goods such as bicycles, baseball, shooting, and lacrosse.
Properties of Scandium
Scandium has a specific gravity of 2.99, a melting point of 1,541°C, and a boiling point of 2,836°C. Scandium is gradually soluble in water and dilute acids. It dissolves readily in hot water and acids.
However, it does not react with a 1:1 mixture of hydrofluoric acid and nitric acid. This is believed to be due to the formation of a passive layer. When scandium is burned in air, it emits a yellow, glowing flame and forms scandium (III) oxide. The oxidation number of scandium is usually +3.
The crystal structure of scandium, which is stable at room temperature and pressure, is a hexagonal close-packed structure (HCP, α-Sc). Upon heating, there are two additional forms (β, δ). The crystal structures are cubic close-packed and face-centered cubic lattice, respectively.
Other Information on Scandium
1. Name of Scandium
The Swedish analyst Lars Fredrik Nilson named scandium from the Latin word Scandia, meaning Scandinavia.
Other known sources of Scandium include Thortveitite, Euxenite, and Gadolinite, which are rare ores produced on the Scandinavian Peninsula and Madagascar. Thortveitite, for example, contains up to 45% scandium as scandium oxide.
2. Formation of Scandium
Electrolysis of an eutectic mixture of potassium, lithium, and scandium chloride at 700-800°C produces the metal scandium.
3. Isotopes of Scandium
There is only one naturally occurring isotope of scandium, 45Sc. There are 13 known radioactive isotopes of scandium. The most stable of these, 46Sc, has a half-life of 83.8 days.
47Sc has a half-life of 3.35 days, 48Sc has a half-life of 43.7 hours, and all the rest have half-lives of less than 4 hours, many of them less than 2 minutes. In addition, scandium has more than 100 nuclear isomers. The mass number of isotopes of Scandium takes between 40 and 54.
Isotopes with a mass number below 45 decay by electron capture and the product is calcium. On the other hand, isotopes with a mass number greater than 45 decay, mainly by beta decay, and the decay product is titanium. Stable isotopes of scandium are synthesized by the r-process during supernova explosions.