The general electronic configuration of the "d"-block elements is (noble gas) ("n" − 1)"d"1–10"ns"0–2. Here "(noble gas)" is the configuration of the last noble gas preceding the atom in question, and n is the highest principal quantum number of an occupied orbital in that atom. For example Ti(Z = 22) is in period 4 so that n = 4, the first 18 electrons have the same configuration of Ar at the end of period 3, and the overall configuration is (Ar)3d24s2. The period 6 and 7 transition metals also add core ("n" − 2)"f"0–14 electrons, which are omitted from the tables below.