Your question looks a bit incomplete as you have the same contents in options a) and d). According to your list, I can't see the correct answer, but I can give you one.The difference between the potential energy of the products of the potential energy of the reactants is equal to the enthalpy of the reaction.
Answer:
<em>K</em><em>+</em><em>Cl</em><em /><em>KCl</em>
Explanation:
because the reaction is between metal Potassium and Non-metal Chlorine
Protactinium
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I think that it is qualitative data