Chemical Corps affiliation with the corps. The Chemical Corps branch insignia consists of a cobalt blue, enamel benzene ring superimposed over two crossed gold retorts. The branch insignia, which was adopted in 1918 by the fledgling Chemical Service, measures .5 inches in height by 1.81 inches in width. Crossed shells with a dragon head was also commonly used in France for the Chemical service. The Chemical Warfare Service approved the insignia in 1921 and in 1924 the ring adopted the cobalt blue enamel. When the Chemical Warfare Service changed designations to the Chemical Corps in 1946 the symbol was retained. The regimental
Term symbol database, neutral atoms are identified as I, singly ionized atoms as II, etc. Neutral atoms of the chemical elements have the same term symbol "for each column" in the s-block and p-block elements, but may differ in d-block and f-block elements, if the ground state electron configuration changes within a column. Ground state term symbols for chemical elements are given below. For light atoms, the spin-orbit interaction (or coupling) is small so that the total orbital angular momentum "L" and total spin "S" are good quantum numbers. The interaction between "L" and "S" is known as "LS coupling," "Russell-Saunders" "coupling"