Which pair of elements is most likely to chemically combine and form ionic bonds, chlorine and chlorine or lithium and chlorine, or carbon and hydrogen, or slfur and oxygen?

I believe the correct answer from the choices listed above is the second option. The pair of elements that is most likely to chemically combine and form ionic bonds would be lithium and chlorine. Lithium is metal and chlorine is nonmetal which as a compound forms ionic bonds. Hope this answers the question.

Chemical --> mechanical --> thermal