How could the appearance of a substance change with out it becoming a different substance

What are the major products produced in the combustion of c10h22 under the following conditions? write balanced chemical equations for each. a. an excess of oxygen b. a slightly limited oxygen supply c. a very limited supply of oxygen d. the compound is burned in air

Write a paragraph that provides examples of each stage of volcanic activity, a description of the volcano, and facts about each stage.

Describe the interaction that occurs between two objects with the same electrical charge.