Group VIA nonmetals

Two lithium atoms each transfer a single electron to one sulfur atom to yield the ionic compound U2S. As an alkali metal (Group lA), lithium easily gives up its single valence electron. As a Group VIA nonmetal, sulfur readily accepts two additional electrons into its valence shell. 

Although the oxides of the other Group lA metals are prepared by different methods, similar descriptions apply to compounds between the Group lA metals (Li, Na, K, Rb, Cs) and the Group VIA nonmetals (O, S, Se, Te, Po). 

This discussion also applies to other ionic compounds between any Group HA metal (Be, Mg, Ca, Sr, Ba) and any Group VIA nonmetal (O, S, Se, Te). 

Describe some important reactions and compounds of the heavier Group VIA nonmetals... 

Group VIA nonmetals must gain two electrons to form anions with noble gas configurations. 

Nonmetals in odd-numbered periodic groups favor odd oxidation numbers, whereas those in even-numbered groups favor even oxidation numbers in their compounds. The maximum oxidation number for a representative element is equal to its periodic group number. For example, sulfur (Group VIA) can form both SF4 and SFg. 

Binary acids are compounds in which H is bonded to a Group VIA elemeut other than O or to a Group VILA element they act as acids when dissolved in water. The pure compounds are named as typical binary compounds. Their aqueous solutions are named by modifying the characteristic stem of the nonmetal with the prefix hydro- and the suffix -ic followed by the word acid. The stem for sulfur iu this iustauce is sulfur rather thau sulf. ... 

Binary acid A binary compound in which H is bonded to a non-metal in Group VILA or a nonmetal other than oxygen in Group VIA. 

Each Group VIA element is less electronegative than its neighboring halogen. Oxygen and sulfur are clearly nonmetallic, but selenium is less so. Tellurium is usually classified as a metalloid and forms metal-like crystals. Its chemistry is mostly that of a nonmetal. Polonium is a metal. All 29 isotopes of polonium are radioactive. 

Selenium belongs to Group VIA of the Periodic Table of the elements, and is located between sulfur and tellurium. Its chemical and physical properties are intermediate between those of a metal and a nonmetal. Furthermore, selenium resembles sulfur more closely than tellurium. The atomic number and atomic mass of the element are 34 and 78.96, respectively there are six natural isotopes, Se, Se, Se, Se, Se, Se, whose abundance is 0.87, 9.02, 7.58, 23.52, 49.82, and 9.19%, respectively. Additionally, there are ten short-lived manmade isotopes of which Se, Se, and Se are the most utilized in neutron activation analysis and radiology (Newland... 

Group VIA, like the preceding groups, shows the trend from nonmetallic to metallic as you proceed from top to bottom of the column of elements. Oxygen and sulfur are strictiy nonmetallic. Although the chemical properties of selenium and tellurium are predominantly those of nonmetals, they do have semiconducting allotropes as expected of metalloids. Polonium is a radioactive metal. 

Complex carbides are very numerous. Many newer compounds of this class have been discovered and their stmctures elucidated (20). The octahedron M C is typical where the metals arrange around a central carbon atom. The octahedra may be coimected via corners, edges, or faces. Trigonal prismatic polyhedra also occur. Defining T as transition metal and M as metal or main group nonmetal, the complex carbides can be classified as (/)... 

In contrast, nonmetals in groups 16 (VIA), 17 (VIIA), and 18 (VIIIA) are characterized by being very inefficient at conducting both electricity and heat. In fact, most can be thought of as insulators because they are such poor conductors of electricity and heat. To confuse matters even more, some references hst semiconductors as a special group of metals. 

The Oxygen Group (Oxidizers and Nonmetals) Periods 2 to 6, Group 16 (VIA)... 

Elements bordering the staircase (boron, silicon, germanium, arsenic, antimony, tellurium, polonium, and astatine) are called metalloids because they have properties between those of metals and nonmetals. Chemists debate the membership of certain elements (especially polonium and astatine) within the metalloids, but the list here reflects an inclusive view. You can find these elements in Groups lllA, IVA, VA, VIA, and VllA. 

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