Question

A ____ reaction occurs when two substances combine to from one substance. An example of this kind of reaction is rusting, in which iron reacts with oxygen

*replacement
*synthesis

Answer 1

synthesis

Step-by-step explanation:

in synthesis reactions, 2 compounds or elements react to form one. decomposition reactions are the opposite of this, meaning one compound breaks down into 2 (or more) compounds or elements.

Answer 2

A ___synthesis _ reaction occurs when two substances combine to from one substance. An example of this kind of reaction is rusting, in which iron reacts with oxygen

Step-by-step explanation:

Synthesis reactions are characterized by being exothermic, where two compounds react to generate a new one. In the case of iron and oxygen, the following reaction occurs:

2Fe + 02 ---> 2Fe0 (iron oxide)