D. similar number of nuetrons
Explanation:
Reaction equation for this reaction is as follows.

It is given that
= 0.0118.
According to the ICE table,

Initial: 0.86 0.86 0 0
Change: -x -x +x +x
Equilibrium: 0.86 - x 0.86 - x x x
Hence, value of
will be calculated as follows.

0.0118 = 
x = 0.084 atm
Thus, we can conclude that
is 0.084 atm.
Answer: metal
Explanation: it says element so conductor and semiconductor are out and a halogen is a group of gases on the periodic table so this brings up to a conclusion of metal.
NOTE: I am not a professional***