In which of the following atoms are valence electrons in the highest average potential energy states? Cl
Br
F
I

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.

c) should be the answer.

0.88m hope i am correct : )