Green Cross (chemical warfare) The mixture was chlorine-phosgene, with 95% and 5%. Green Cross (chemical warfare) Green Cross (Grünkreuz) is a World War I chemical warfare pulmonary agent consisting of chloropicrin (PS, Aquinite, Klop), phosgene (CG, Collongite) and/or trichloromethyl chloroformate (Surpalite, Perstoff). Green Cross is also a generic World War I German marking for artillery shells with pulmonary agents (chemical payload affecting the lungs). The tip of the projectile with the fuse end painted green and a green cross at the bottom of the cartridge. Other Green Cross mixtures were based on phosgene and/or diphosgene. The first use of Green Cross was on May
Chemical element neutrons) for a particular isotope of an element, with this number combined with the pertinent element's symbol. IUPAC prefers that isotope symbols be written in superscript notation when practical, for example C and U. However, other notations, such as carbon-12 and uranium-235, or C-12 and U-235, are also used. As a special case, the three naturally occurring isotopes of the element hydrogen are often specified as H for H (protium), D for H (deuterium), and T for H (tritium). This convention is easier to use in chemical equations, replacing the need to write out the mass number for each atom.