Final answer:
The question covers various aspects of Chemistry including nuclear reactions, balancing chemical equations, identifying catalyzed reactions, and understanding exchange reactions. It touches upon alpha decay, a common type of nuclear reaction, and the fundamental practice of equation balancing relevant to chemical reactions.
Step-by-step explanation:
The question pertains to whether certain nuclear reactions are possible and involves completing and balancing chemical equations similar to those used with industrial chemicals. Additionally, it asks for identifying catalyzed reactions and understanding exchange reactions. These concepts relate to chemical equations, nuclear reactions, and reaction mechanisms within the realm of Chemistry.
For the hypothetical nuclear reaction U → Ra + He, it appears to describe the decay of Uranium (U) into Radium (Ra) and Helium (He), which is a form of alpha decay and is indeed possible as uranium isotopes like Uranium-238 decay into radium isotopes by emitting alpha particles (which are equivalent to Helium nuclei).
The task involving industrial chemicals is about balance of chemical equations, a fundamental practice in Chemistry where one ensures the number of atoms for each element is the same on both sides of the equation. As for the identification of catalyzed reactions among pairs of reaction diagrams, the catalyzed one typically shows a lower activation energy pathway. Lastly, an exchange reaction involves both the formation and breaking of bonds where reactants are rearranged to form products.