To determine the oxidation state of the chromium atom in potassium dichromate K2Cr2O7 , we can use the oxidation state rules.1. The oxidation state of an element in its elemental form is 0.2. The oxidation state of a monatomic ion is equal to its charge.3. The sum of the oxidation states of all atoms in a neutral compound is 0, and in a polyatomic ion, it is equal to the charge of the ion.In K2Cr2O7, we have potassium K , chromium Cr , and oxygen O atoms. The oxidation state of potassium K is +1, as it is an alkali metal and forms a monatomic ion with a charge of +1. The oxidation state of oxygen O is typically -2.Now, let's set up an equation using the oxidation state rules:2 K + 2 Cr + 7 O = 0 since the compound is neutral We know the oxidation state of K is +1 and O is -2, so we can substitute those values into the equation:2 +1 + 2 Cr + 7 -2 = 0Simplify the equation:2 + 2 Cr - 14 = 0Now, solve for the oxidation state of Cr:2 Cr = 12Cr = +6So, the oxidation state of the chromium atom in potassium dichromate K2Cr2O7 is +6.