When Germany unleashed chlorine gas at Ypres in 1915, it marked the dawn of modern chemical warfare. Soldiers had no masks, no protection—only panic and death. Was this the most inhumane weapon of WWI ...

A small piece of sodium metal is placed in a flask of chlorine gas. A little water helps expose the sodium so it can react with the chlorine gas. The reaction releases a lot of heat as the ionic ...

An emergency situation at the Grand Canyon forced the closure of inner corridor trails, including the Bright Angel Trail, park officials said.

Trails in Grand Canyon National Park were closed due to a chlorine gas leak. Chlorine is used as a disinfectant in the Roaring Springs area of the park. The trails have since reopened NORTH RIM ...