Chlorine

Chlorine is an original member of the Elements of Doom which are a team consisting of living elements that take over a Russian nuclear plant and needed more human specimens to recreate all the elements from the periodic table. The Avengers come to the aid of the Russians as they were flying over Soviet airspace. They land at the Russian nuclear plant and come across the first element Vanadium. Wonder Man would smash through Vanadium’s body and then the rest of the Avengers enter the plant. They see four more elements- Carbon, Phosphorus, Chlorine and Radium inside so a battle ensues. The Elements of Doom are interested in the Avengers and wish to make them into specimens.  Captain America orders a strategic withdrawal when the element Chlorine unleashes a poisonous gas. The Falcon realizes the Wasp is missing and goes back to get her but he is knocked out by Vanadium. Apparently he reassembled his atoms after Wonder Man’s attack and brings back the Falcon as a potential specimen. 

The Wasp tells Captain America she was knocked out for a bit after inhaling some of Chlorine’s gas. When she awoke she saw Phosphorus place a Soviet technician inside a machine. The man’s atoms were rearranged and was transformed into another element- Cobalt. They wanted to recreate all the elements known to man and they had the Falcon. Ms. Marvel and the Beast would use the laser cannon from a tank to destroy the fusion reactor while the rest of the Avengers saved the Falcon. The laser blast splits the fusion reactor and exposes its molten core. Chlorine and the Elements of Doom are caught in a hot rain of nuclear plasma. The thermonuclear mixture of electrons and charged atoms swiftly breaks down their atomic structures.  

Creation

Chlorine was created by Bill Mantlo, John Byrne, Daniel Green and Frank Springer in 1979 and first appeared in The Avengers # 188. 

Powers & Abilities

Chlorine is a living element that can emit a poisonous gas cloud from his hands.