Identify the missing particle in the following nuclear equation: U → ? + He + 2 g

Question

Identify the missing particle in the following nuclear equation:  U → ? +  He + 2  g

Quizplus · Accepted Answer

In the given nuclear equation, the sum of the atomic numbers and mass numbers on both sides of the equation should be equal. 
Atomic number (Z) represents the number of protons in the nucleus, and the mass number (A) represents the total number of protons and neutrons in the nucleus.

On the left-hand side of the equation, we have:
Atomic number (Z) = 92
Mass number (A) = 235

On the right-hand side of the equation, we have:
Number of alpha particles (helium nuclei) = 1
Number of gamma particles = 2

So, the missing particle should have an atomic number of 90 and a mass number of 231 to balance the equation. 
Looking at the answer choices, only option D, 11ea67b3_9694_008b_8b3b_4fb4a34caab5_TB6103_11 Th, satisfies this requirement.

Identify the Missing Particle in the Following Nuclear Equation