Which of the following non-metals reacts most readily with metals?

Out of the given options, chlorine reacts most readily with metals. Chlorine is a highly reactive non-metal that readily reacts with most of the metals to form ionic compounds called metal chlorides. When chlorine gas comes into contact with a metal, it gains one electron to form chloride ions, which have a stable electronic configuration of a noble gas. The reaction is exothermic and produces a white solid or colorless gas, depending on the metal. Chlorine gas is used in many industries, such as water treatment, chemical manufacturing, and paper production, due to its strong oxidizing properties and ability to react with metals. Therefore, the correct answer is "Chlorine".