Reaction coordinates represent: A. The balanced equation for a chemical reaction. B. The change in pH for a chemical reaction. C. The potential energy change for a chemical reaction. D. None of the above

C. The potential energy change for a chemical reaction.

Explanation:

The reaction coordinate q illustrates, graphically, the energy changes during exothermic and endothermic reactions. This graphical representation of the energy changes in the course of a chemical reaction is known as reaction coordinates. A reaction coordinate is a graphical sequence of steps by which the reaction progresses from reactants through activated complexes to products. Reaction coordinates explain how far a reaction has proceeded towards the products or from the reactants.

From the images attached below, we can see the reaction coordinates in the reaction profiles.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.