Introduction to Chemical Reactions Answers

Which best describes what happens to the atoms in a chemical reaction?

What must occur in order for a chemical reaction to be specifically classified as endothermic instead of exothermic?

Which is an example of a chemical reaction?

When baking soda and vinegar react, the surface bubbles. What does this most likely indicate?

Theresa creates an experiment where she mixes two red-colored substances together in a container and observes the solution slowly changing from red to blue for the next eight minutes. The solution becomes completely blue after eight minutes.

When liquid silver nitrate and liquid sodium chloride are combined, solid silver chloride forms along with a new liquid, sodium nitrate. Which substance represents the precipitate?

For a science project, Janet performs four experiments that are supposed to show a chemical reaction. She displays her results in a table.

Reggie and Charlotte are baking oatmeal cookies. They dip the baked cookies in melted chocolate. The chocolate cools to form a hardened coating. Reggie argues the entire chocolate-covered cookie has undergone a chemical change. Charlotte disagrees, saying only the original oatmeal cookie has undergone a chemical change, not the chocolate coating.

Which is evidence that a chemical reaction has likely occurred?

A Venn diagram is used to compare and contrast different topics. The items that are unique to each topic are represented in the separate sections of the circles, and the items that are common to both topics are represented in the center overlapping sections. Harlow creates this Venn diagram comparing and contrasting endothermic and exothermic processes.