Answer: C. [tex]2Mg+O_2\rightarrow 2MgO+Energy[/tex]
Explanation:
Synthesis is a reaction in which two or more than two reactants combine to give one product. Magnesium loses two electrons to form [tex]Mg^{2+}[/tex] and oxygen gains two electrons to form [tex]O^{2-}[/tex]
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
[tex]2Mg+O_2\rightarrow 2MgO+Energy[/tex]
