Question

in a _____ reaction, two or more elements or compounds form one product.
a) decomposition
b) single replacement
d) double replacement
c) combination

Explanation:

A combination reaction involves two or more substances (elements or compounds) combining to form a single product. Decomposition is the opposite (one substance breaks into multiple), single - replacement involves one element replacing another in a compound, and double - replacement involves the exchange of ions between two compounds.

Answer:

D. combination