How Matter Changes Review

1. In an endothermic reaction, the temperature decreases because_____.

• energy is absorbed

• energy is created

• energy is destroyed

• energy is released

The definition of an exothermic reaction is a reaction that__________

• consumes heat

• releases heat

• consumes nuclear radiation

• releases matter

1. A scientist combines chemicals and produces an exothermic reaction. What byproduct of this reaction would show that it is exothermic?

• heat

• coolness

4. In a chemical formula, the reactants are _____.

• on the left side of the arrow

• on the right side of the arrow

• do not have the same elements as the products

Catalysts help ___________

• decrease the speed/rate of a reaction

• increase the speed/rate of a reaction

What is an example of an endothermic reaction

• digestion of food

• combustion

• photosynthesis

• evaporation of water

8. All of the following are indicators of a chemical reaction except one. Which one is NOT an indicator that a chemical reaction has taken place?

• The production of heat/light

• a color change

• the production of gas bubbles

• dissolving of a substance into another

8. Two chemicals mixed in a beaker cause it to become cold to touch. Which term describes this chemical reaction?

• endothermic

• exothermic

8. When a scientist mixed two chemicals, an exothermic reaction takes place. Which of the following would be proof that the reaction was exothermic?

• a change of color

• a change of state

• a temperature decrease

• a temperature increase

12. The idea that matter is neither created nor destroyed in chemical reactions is known as the:

• law of conservation of chemicals.

• 0. law of conservation of energy.

• 0. law of conservation of mass.

• 0. second law of thermodynamics.