Elements in group 17 (VIIA) are least likely to form an ionic bond with elements in: Group 2a (IIA)
Group 17 (VIIA)
Group 3 (IIIA)
Group 1 (IA)

a corroding iron, if that's one of your choices

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.

the answers are

c and c