# Question #ee902

##### 1 Answer

Feb 15, 2017

Mn O.N =+7

#### Explanation:

We all know oxygen has an oxidation number = 2

So when we have a charge on the molecule.

It means the sum of all the oxidation number of the molecule should add up to give that charge.

Like the ex. You have asked

The molecule has -1 as the charge.

So,

(O.N of Mn + O.N of Oxygen should equal to -1)

We all know oxidation number(O.N) of O is -2

So,

Let X be the O.N of Men

I.e.

Or X=-1+8

I.e. X=+7

Hope you understand. :)