Final answer:
The charge on ion X in the ionic formula XCl₂ must be +2 to balance out the two -1 charges from the chloride ions, making the compound neutral.
Step-by-step explanation:
If we are given the ionic formula XCl₂ and we need to determine the charge on ion X, we should know that chlorine (Cl) typically has a -1 charge when it is part of an ionic compound. Considering there are two chloride ions, we can say the total negative charge is -2. Now, for the compound to be neutral, the charge on X must balance out this -2 charge. Therefore, ion X must have a +2 charge. In many ionic compounds, such as MgCl₂, the magnesium ion has a charge of +2, while each chlorine ion has a charge of -1. Using these conventions, the correct answer to the given question would be C. +2, ensuring the overall neutrality of the compound.