Question

a reaction where reactants are methane and elemental oxygen, and carbon dioxide and water are products is a _______________ reaction. it may be helpful to write the reaction equation before answering the question.
disproportionation reaction
combustion reaction
decomposition reaction
combination (synthesis) reaction

Explanation:

Combustion reactions involve a substance reacting with oxygen to produce heat and usually carbon - containing products like carbon dioxide and water. Methane ($CH_4$) reacting with oxygen ($O_2$) to form carbon dioxide ($CO_2$) and water ($H_2O$) follows the general pattern of a combustion reaction. The reaction equation is $CH_4 + 2O_2
ightarrow CO_2+2H_2O$. Disproportionation reactions involve an element being both oxidized and reduced in the same reaction. Decomposition reactions involve a single reactant breaking down into multiple products. Combination (synthesis) reactions involve multiple reactants combining to form a single product.

Answer:

B. combustion reaction