Question

Consider this reaction: 2HgO→2Hg + O2.

Which sentence is the best explanation for why this reaction is a decomposition reaction?

Responses

This is a decomposition reaction because oxygen is one of the reactants.

This is a decomposition reaction because oxygen is one of the reactants.

This is a decomposition reaction because the equation is balanced.

This is a decomposition reaction because the equation is balanced.

This is a decomposition reaction because there are two products.

This is a decomposition reaction because there are two products.

This is a decomposition reaction because there is only one reactant.

Answer 1

"This is a decomposition reaction because there is only one reactant."

Explanation: decomposition reactions involve a single compound breaking down into two or more simpler substances — here HgO decomposes into Hg and O2.