Atomic properties halogen family elements

The fact that x(0) and k tend to vary inversely means that atomic properties related to electronegativity may sometimes not change monotonically within a family of elements. A number of examples of this have been observed and discussed [13-16,19-24]. For instance, in a recent computational study of the electrostatic potentials associated with naphthalene derivatives, we found evidence that the electron-attracting tendencies of the halogens in 1-halonaphtha-lenes increase in the order F < Br < Cl [24]. 

A column of the periodic table is called a family. Some families have special names. Group IA elements are called alkali metals, group IIA elements are called alkaline earth metals, group VIIA elements are called halogens, and group VIIIA elements are called the noble gases. The group B elements are called transition elements. Elements with atomic numbers from 58 to 71 are called lanthanides, and elements with atomic numbers from 90 to 103 are called actinides. Families have similar chemical and physical properties. For example, the alkali metals are soft metals at room temperature they are shiny, conduct... 

A second reason for the vast number of organic compounds is that carbon atoms can form stable bonds with other elements. Several families of organic compounds (alcohols, aldehydes, ketones, esters, and ethers) contain oxygen atoms bonded to carbon. Others contain nitrogen, sulfur, or halogens. The presence of these elements confers a wide variety of new chemical and physical properties on an organic compound. 

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