Magnesium has two valence electrons, and oxygen has six valence electrons. What type of bonding is likely to occur between a magnesium atom and an oxygen atom?

Magnesium will give its two valence electrons to oxygen and it will have a charge of 2 + (positive). It will also complete its octet, getting balanced.

Oxygen will take two electrons from magnesium getting a charge of 2 - (negative). It will also complete its octet.

When making the formula, the two charges will cancel out each other giving the formula MgO.

It is an ionic bond.

Magnesium and Oxygen atoms would cause an ionic compound.