Answer:
The correct reaction is as follows:
2Mg + O2 → 2MgO
3. Synthesis
Step-by-step explanation:
Chemical reactions are of different types depending on how they occur. One of these types is called SYNTHESIS OR COMBINATION REACTION. A synthesis reaction is that reaction in which two atoms of two elements are chemically combined to form a single molecule or compound. That is;
A + B → AB.
This is the case in this question where atoms of Magnesium (Mg) and oxygen (O) reacted to form a single compound of Magnesium oxide (MgO). Hence, it is said to be a SYNTHESIS REACTION.