Final answer:
The nuclear equation for the alpha decay of 23892U is 23892U → 42He + 23490Th, where a helium nucleus is emitted and thorium-234 is the daughter isotope.
Step-by-step explanation:
The nuclear equation for the alpha decay of 23892U involves the release of an alpha particle from the nucleus of the uranium atom. The alpha particle is represented by the helium nucleus, 42He, which has two protons and two neutrons. The product of this decay is a new element with an atomic number two less and a mass number four less than the original uranium. Therefore, the product of the uranium-238 decay is thorium-234 (23490Th). The resulting nuclear equation is: 23892U → 42He + 23490Th