Which of the following are isotopes?
(a) 80 Br. (b)8°Br-1 (c) 79Br (d) 80Se

the answer is barium and copper bromide

i think its 100.

hope this !

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.