Respuesta :

Answer:

synthesis reaction

Explanation:

Types of reactions:

A + B = AB synthesis

AB = A+B decomposition

AB + C = AC + B single replacement

AB + CD = AC + BD double replacement
synthesis reaction
the balanced equation would be:
2Na(s) + 1H2(g) -> NaH
it could be 2NaH2, but formulas that can be simplified should be simplified.