The oxidation number of X in \(XO_{4}^{3+}\) is

The oxidation number of an element in a chemical compound is a number that represents the charge that an atom of that element would have if the molecule was completely ionic. In a compound, the sum of all the oxidation numbers must equal the net charge on the molecule. In the case of \(XO_{4}^{3+}\), the oxidation number of X can be determined by using this rule. The net charge on the molecule is +3, which means that the sum of all the oxidation numbers of the atoms in the molecule must equal +3. Since the oxidation number of oxygen is always -2, the oxidation number of X can be calculated as follows: \[X + 4(-2) = +3\] Solving for X, we get: \[X = +5\] Therefore, the oxidation number of X in \(XO_{4}^{3+}\) is +5.