Waht is the total charge of these ions

- four sodium ions
- eight manganese(IV) ions
-three nitride ions
please explain how to work it out :)

Ionic charges are cummulative, meaning they add up, such as below:

4 x Na(1+)= 4+
8 x Mn(4+)=32+
3 x N(3-)= 9-

http://www.kentchemistry.com/links/Atomi…

bottom of the page explains how to determine the charges of your ions