Refer to the Newsela article "How You Can Make a Solar Oven To Cook with a Pizza Box."

What is the author's purpose in mentioning variables in designing the solar oven?

to show how easy it is to produce solar energy

to encourage readers to vary the design

to explain how wasteful solar energy production can be

to show the author did not think too hard about the design

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.