Make up the equations for the reactions of combustion of the following substances in oxygen

Make up the equations for the reactions of combustion of the following substances in oxygen: a) magnesium b) calcium c) silicon d) hydrogen e) silane (SiH4) .Set the coefficients.

a) Magnesium is a divalent metal, therefore there are no indices when combined with oxygen.
2Mg + O2 = 2MgO
b) Calcium is a divalent metal, therefore, when combined with oxygen, there are no indices.
2Ca + O2 = 2CaO
c) Silicon in combination with oxygen has a valency IV, since oxygen is divalent, it will have an index of 2.
Si + O2 = SiO2
d) Hydrogen has a constant valence I, since oxygen is divalent, then hydrogen will have an index of 2.
2H2 + O2 = 2H20
e) Silane, when combined with oxygen, decomposes into silicon oxide (IV) and water.
SiH4 + 2O2 = SiO2 = 2H2O