What are the physical and chemical properties of halogens?

Molecules of all halogens are diatomic. What this means is that their molecules exist with two atoms each. Halogens have seven valence electrons because halogens have one electron missing, they form negative ions and are highly reactive.

Explanation:

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.