Answer:
[tex]Z\text{ = +6}[/tex]Explanation:
Here, we want to get the value of the oxidation number of Z
Generally, hydrogen has an oxidation number of +1, while oxygen has an oxidation number of -2
The total oxidation number is zero
Thus:
[tex]\begin{gathered} 2(+1)\text{ + Z + 4\lparen-2\rparen = 0} \\ 2+Z-8\text{ = 0} \\ Z-6\text{ = 0} \\ Z\text{ = +6} \end{gathered}[/tex]