Answer:
Synthesis
Decomposition
Step-by-step explanation:
Synthesis involves combining two elements to form a single product
2Mg + O2 —> 2MgO
From the above, two reactants produced one product.
Combustion involves burning substance in the presence of O2 and this produces CO2 and H20. E.g the Combustion of methane.
CH4 + 2O2 —> CO2 + 2H20
From the above, two reactants produced two products
Double displacement reaction is a reaction in which the atoms interchange by the decomposition of the two reactants, to produce new compounds. E.g the neutralisation of acid by a base to form salt and water.
HCl + NaOH —> NaCl + H2O
From the above, two reactants produced two products.
Decomposition involves the break down of a single compound to form two or more elements or compound. E.g the Decomposition of KClO2 to produce KCl and O2
2KClO2 —> 2KCl + 3O2
From the above, one reactant form two products.
Single displacement reaction involves the displacement of less reactive element by a more reactive element from a compound.
Zn + 2HCl —> ZnCl2 + H2
From the above, two reactants produced two products.
We see clearly that synthesis involves two reactants to produce one product and Decomposition involves one reactant to produce two products.