How would you balance the following equation mg + o₂ = mgo?

Answer: Mg + O₂ = MgO

In this equation, Mg is magnesium, O is Oxygen, and the product we get is MgO, known as magnesium oxide. 

This type of reaction is known as a combination reaction or synthesis reaction. Like A + B = AB, this is a combination reaction. If we see in the periodic table magnesium is metal and oxygen is non-metal, they make an ionic bond.

First, let’s add up the number of atoms we have on each side of the equation. There is one atom of magnesium, two atoms of oxygen and one atom of magnesium and one atom of oxygen on the product side. If nothing is written on the coefficient, we assume it to be 1. This equation is not balanced. To make the oxygen equal, we will have to balance the equation. We can put 2 in the coefficient place in front of MgO to make oxygens equal. We have one time two, and the oxygen in the equation is balanced. We have one magnesium in the reactant; when we balance the oxygen, we multiply one magnesium two times, giving us two magnesium atoms. After this, we add 2 to the coefficient of Mg in the reactant. Now the equation is balanced, and the final equation will be

2Mg + O₂ = 2MgO

This equation is an exothermic reaction; when you have magnesium and ignite, it combines with the oxygen and gives bright light. And it is dangerous for the eyes if we are very close to it. In the periodic table, the Mg has a 2+ ionic charge, and oxygen has a -2 ionic charge; therefore, in the result, the net charge is 0 because 2+ and 2- cancel out. In this reaction, solid magnesium reacts with the oxygen in the air and gives magnesium oxide, releasing heat.