Magnesium oxide is a binary ionic compound. from the formula mgo, how do you know that mg is the metal?

See below.  

Step-by-step explanation:

Method 1:

You know that oxygen is a non-metal.

If the compound is ionic, the oxygen must be combined with a metal.

The Mg must be a metal.

Method 2:

In the formulas of ionic compounds, the positive ion (usually a metal) is written first.

well in order to answer this question you have to provide more information < 3

answersilicon (si); oxygen (o);