consider the nuclear equation below.\n$_{86}^{222}rn\\longrightarrow_{?}^{218}po + _{2}^{4}he$\nwhich is the…

consider the nuclear equation below.\n$_{86}^{222}rn\\longrightarrow_{?}^{218}po + _{2}^{4}he$\nwhich is the missing value that will balance the equation?\n84\n86\n88\n90
Answer
Explanation:
Step1: Recall nuclear - equation balance rule
In a nuclear equation, the sum of atomic numbers on the left - hand side must equal the sum of atomic numbers on the right - hand side. The atomic number of $^{222}{86}Rn$ is 86. The atomic number of $^{4}{2}He$ is 2. Let the atomic number of $^{218}_{?}Po$ be $x$.
Step2: Set up the equation
We have the equation $86=x + 2$.
Step3: Solve for $x$
Subtract 2 from both sides of the equation: $x=86 - 2=84$.
Answer:
A. 84