The boron family contains elements in group 13 of the periodic talbe and include the semi-metal boron (B) and the metals aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Aluminum, gallium, indium, and thallium have three electrons in their outermost shell (a full s orbital and one electron in the p orbital) with the valence electron configuration ns 2 np 1 . The elments of the boron family adopts oxidation states +3 or +1. The +3 oxidation states are favorable except for the heavier elements, such as Tl, which prefer the +1 oxidation state due to its stability; this is known as the inert pair effect . The elements generally follow periodic trends except for certain Tl deviations: Group 13: Chemical Reactivity The boron family contains the semi-metal boron (B) and metals aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Group 13: Physical Properties of Group 13 The boron family contains the semi-metal boron (B) and metals aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Chemistry of Boron (Z=5) Boron is the fifth element of the periodic table (Z=5), located in Group 13. It is classified as a metalloid due it its properties that reflect a combination of both metals and nonmetals. Boranes and Borohydrides Chemistry of Aluminum (Z=13) Aluminum (also called Aluminium) is the third most abundant element in the earth's crust. It is commonly used in the household as aluminum foil, in crafts such as dyeing and pottery, and also in construction to make alloys. In its purest form the metal is bluish-white and very ductile. It is an excellent conductor of heat and electricity and finds use in some wiring. When pure it is too soft for construction purposes but addition of small amounts of silicon and iron hardens it significantly. Aluminium Metallurgy Aluminum Oxide Case Study: Conversion of Bauxite Ore to Aluminum Metal Chemistry of Gallium (Z=31) Gallium is the chemical element with the atomic number 31 and symbol Ga on the periodic table. It is in the Boron family (group 13) and in period 4. Gallium was discovered in 1875 by Paul Emile Lecoq de Boisbaudran. Boisbaudran named his newly discovered element after himself, deriving from the Latin word, “Gallia,” which means “Gaul.” Elemental Gallium does not exist in nature but gallium (III) salt can be extracted in small amounts from bauxite and zinc ores. Chemistry of Indium (Z=49) Indium has the chemical symbol In and the atomic number 49. It has the electron configuration [Kr] 2s22p1 and may adopt the +1 or +3 oxidation state; however, the +3 state is more common. It is a soft, malleable metal that is similar to gallium. Indium forms InAs, which is found in photoconductors in optical instruments. The physical properties of indium include its silver-white color and the "tin cry" it makes when bent. Indium is soluble in acids, but does not react with oxygen at room tempera Chemistry of Thalium (Z=81) Thallium has the chemical symbol Tl and atomic number 81. It has the electron configuration \([Xe] 2s^22p^1\) and has a +3 or +1 oxidation state. As stated above, because thallium is heavy, it has a greater stability in the +1 oxidation state (inert pair effect). Therefore, it is found more commonly in its +1 oxidation state. Thallium is soft and malleable. Chemistry of Nihonium (Z=113) In studies announced jointly by the Joint Institute for Nuclear Research in Dubna, Russia, and the Lawrence Livermore National Laboratory in the U.S., four atoms of element 113 were produced in 2004 via decay of element 115 after the fusion of Ca-48 and Am-243. Thumbnail: Crystals of 99.999% gallium. (CC-SA-BY 3.0; Foobar)