The cluster theory of chemical clusters has made it possible to analyze and categorize a wide range of chemical clusters. These clusters can be expressed in a cluster configuration form represented by K*=DzCy. On a close observation the Dz which follows the 14n series can be regarded as similar to a group number of chemical elements in a conventional periodic table. Likewise, the symbol Cy which follows the 12n series can be regarded as similar to the period of chemical elements on the periodic table. Selected cluster groups ranging from D0 to D20 and their corresponding periods have been worked out, they can be used to identify chemical clusters ranging from D0 to D20 and their tables have been presented towards the end of the book. In addition, more than a hundred examples have been analyzed and categorized, and each one of them can be located at the appropriate position in the constructed tables. This means that an expanded periodic table which accommodates all known clusters ranging from chemical elements, compounds and chemical complexes can be constructed. In this regard according to cluster theory, even a chemical element on its own is regarded as a chemical cluster.