Noble gas elements

The highest electron affinities are found at the top right of the periodic table (Fig. 14.4 see also Fig. 1.47). The electron affinity of an element is a measure of the energy released when an ion is formed. Except for the noble gases, elements near fluorine have the highest electron affinities, so we can expect them to be present as anions in compounds with metallic elements. For the same reason, these elements commonly have negative oxidation states in the covalent compounds they form with other nonmetallic elements. 

Apart from the atomic noble gases, elemental substances may be classified as metallic or covalent, according to their structures and properties at room temperature and ambient pressure. Covalent elemental substances may be subdivided as molecular or non-molecular, the latter category including one-, two- or three-dimensional structures. There is a grey area between the extremes of the three-dimensional covalent structure and the typical metal semi-metallic or metalloid behaviour is found in a number of cases. Even iodine, prima facie a molecular solid, has incipient metallic properties. In this section, we explore this grey area and consider the factors that determine which type... 

Noble gases Elements in Group 18 (VIIIA) of the periodic table. 

Noble gases Elements of periodic Group VIIIA also called rare gases formerly called inert gases. 

Plan We use the given Z value to find the element in the periodic table and see where its group lies relative to the noble gases. Elements in Groups 1 A, 2A, and 3A lose electrons to attain the same number as the nearest noble gas and become positive ions those in Groups 5A, 6A, and 7A gain electrons and become negative ions. 

Newton (N). The SI unit of force. (11.1) nitrogen fixation. The conversion of molecular nitrogen into nitrogen compounds. (21.1) noble gas core. A representation in an electron configuration that shows in brackets the most recently completed noble gas. (6.9) noble gases. Elements in Group 8A (He, Ne, Ar, Kr, Xe, and Rn). (2.4)... 

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