Answer : 1. "+6"
Explanation :

Answer: A) +6 Explanation: We will rewrite the formula as an equation. 2K + 2Cr + 7O = 0 The zero comes from there being no overall charge on the compound. Each oxidation number is represented by the element's symbol. Since this compound is not a peroxide or superoxide, the oxidation value for O is -2 K being in group 1 has a +1 charge and therefore has an oxidation number of K is +1 Now, by putting known values in we have: 2(+1) + 2(Cr) + 7(-2) = 0 2 + 2Cr -14 = 0 2Cr = +12 Cr = +6.