I believe the correct answer is C, but I'm 100% on this. Hope this helped though!
-TTL
Dynamic equilibrium means that the proportion is equal. The fact that the equation is at equilibrium suggests that the equation is balanced and therefore the answer must be 2.0 mol because that allows the products and reactants to level out...
I think the answer is D not too sure tho
A gamma ray has a mass and atomic number of 0 meaning it doesn’t effect the nucleus.
E.g
60 60 0
Co —> Co + gamma ray
27 27 0
This is displacement reaction.