Final answer:
Given the charge of the chromate ion is 2-, the correct formula for the ionic compound with element X assuming a 2+ charge would be XCrO4. This results in a neutrally charged compound, which is option (d) in the given choices.
Step-by-step explanation:
To determine the correct formula for the ionic compound that results from element X, a fictional metal, reacting with a chromate ion (CrO42-), we need to consider the charges on the metal and the nonmetal ions. A chromate ion has a charge of 2-, which must be balanced by the charge of the metal ion from element X to form a neutrally charged compound. If we assume element X forms a 2+ charge when it becomes an ion (which is common for many metals), the correct formula for the ionic compound would be XCrO4, where one X2+ ion balances one CrO42- ion.
Without knowing the specific charge of the fictional element X, the correct formula among the given options is (d) XCrO4, assuming X has a +2 charge. If X had a different charge, this would affect the subscripts in the formula to ensure the overall charge is neutral.