Question Detail
Question
What is the daughter nucleus formed when Uranium-238 undergoes alpha decay?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Alpha decay removes 2 protons and 2 neutrons (mass number -4, atomic number -2), converting Uranium-238 (Z=92) into Thorium-234 (Z=90).
Hint
Alpha decay reduces the mass number by 4 and the atomic number by 2 — check the periodic table for the element two places before uranium.