Which metal in following compounds is not present in fractional oxidation state?

Step-by-step solution

The oxidation state of the metal is evaluated for each compound to identify which one is not fractional. A) For Fe ₃ O ₄ , the oxidation state x satisfies 3x + 4(-2) = 0 , yielding x = +8/3 , which is fractional. B) Similarly, for Mn ₃ O ₄ , 3x + 4(-2) = 0 gives x = +8/3 , a fractional value. C) For Pb ₃ O ₄ , the same equation 3x + 4(-2) = 0 results in x = +8/3 , also fractional. D) In Na ₂ S ₄ O ₆ , sodium has a fixed oxidation state of +1 , while sulfur's state from 2(+1) + 4x_ S + 6(-2) = 0 is x_ S = +5/2 (frac