STANDARD I: Students will understand the nature of changes in matter.

1. STANDARD I: Students will understand the nature of changes in matter.

2. Objective 1: Describe the chemical and physical properties of various substances. Which of the following is true of chemical properties? a. They describe the phase the substance is in. b. They describe characteristics of a substance such as size, color, and shape. c. They explain how the substance reacts with other substances. d. They describe what chemical changes the substance is currently going through. Correct Answer: c 

3. Objective 1: Describe the chemical and physical properties of various substances While investigating the chemical and physical properties of a new substance created in class, Sally and Tyler record the following observations: The new substance is solid. The new substance forms into thin flat sheets. The new substance is smooth. The new substance will burn. The new substance looks like it will tear easily. The new substance looks like it will dissolve in acid easily. Which of their statements would be an inference about a chemical property? a.     The new substance forms into thin flat sheets. b.     The new substance is smooth. c.     The new substance looks like it will tear easily. d.     The new substance looks like it will dissolve in acid easily. Correct Answer: d

4. Objective 1: Describe the chemical and physical properties of various substances A scientist places 10 mL of water in a test tube and heats the liquid over a Bunsen burner for 2 minutes. The liquid boils and escapes as steam. This experiment is a good example of a. a chemical change involving phase changes • a physical change involving phase changes • a chemical change involving chemical reactions • a physical change involving chemical reactions Correct Answer: b

5. Objective 1: Describe the chemical and physical properties of various substances What is one way that a plastic soda bottle is better than a glass one? a.     It is transparent b.     It doesn’t flavor the drink c.     It is recyclable d.     It doesn’t shatter Correct Answer: d

6. Objective 1: Describe the chemical and physical properties of various substances Both hydrogen and oxygen are flammable. Water is made up of 2 parts Hydrogen and 1 part Oxygen, why doesn’t water burn? a.     Water will burn if you get it hot enough. b.     Because water is a liquid and hydrogen and oxygen are gases. c.     When elements combine physically they form new substances with similar properties. d.     When elements combine chemically they form new substances with different properties. Correct Answer: d

7. Objective 1: Describe the chemical and physical properties of various substances A cube of sugar has the following properties. 1. Mass = 2 grams 2. Density = 8 g/cm3 3. Burns when heated 4. Composed of small, white crystals • Bubbles and fizzes when heated Mark each of the following above as a physical property (P) or a chemical property (C). Correct Answers: 1. P 4. P 5. C 2. P 3. C

8. Objective 2: Observe and evaluate evidence of physical and chemical change. As Terry and Jean poured melted chocolate over their ice cream, they noticed that it became hard. They could assume that: a.     The chocolate had changed phases, which is a physical change. b.     The chocolate had changed phases, which is a chemical change. c.     The chocolate had changed into a new substance, which is a physical change. d.     The chocolate had changed into a new substance, which is a chemical change. Correct Answer: a 

9. Objective 2: Observe and evaluate evidence of physical and chemical change. As Terry mixed some kool-aid for her little brother, she noticed that as the powder mixed into the water that the water changed to the same color as the powder. She could assume that: a.     the flavoring dissolved into the water, which is a physical change. b.     the flavoring dissolved into the water, which is a chemical change. c.     the flavoring created a new substance, which is a chemical change. d.     the flavoring created a new substance, which is a physical change. Correct Answer: a 

10. Objective 2: Observe and evaluate evidence of physical and chemical change. Which of the following is an example of a physical change? a. evaporation in a swamp cooler b. electricity produced by a dry cell c digestion of a hamburger • rusting of a car body Correct Answer: a

11. Objective 2: Observe and evaluate evidence of physical and chemical change. During an experiment Joe mixed two chemicals together. The chemicals smoked and a very strange odor came from them. This indicated that: a. one or more chemical changes had taken place. b. one or more physical changes had taken place. c a color change was going to happen next. d. the molecules had diffused throughout the mixture. Correct Answer: a 

12. Objective 2: Observe and evaluate evidence of physical and chemical change. In a laboratory experiment you mix two colorless liquids together. After a few minutes you notice the liquid has turned purple.  What can you infer has happened? a. An acid has formed. b. A base has formed. c A chemical change has occurred. • A physical change has occurred. Correct Answer: c

13. Objective 2: Observe and evaluate evidence of physical and chemical change. Which of the following is an example of a chemical change? a. Baking soda in vinegar b. Freezing water c. Bending steel • Sawing a board Correct Answer: a

14. Objective 2: Observe and evaluate evidence of physical and chemical change. When you turn up the thermostat on your furnace several things happen. Which of these would be considered a chemical change? a.     Air circulates throughout the room. b.     Fuel in the furnace burns. c.     The temperature in the room increases. d.     Heat in the room rises. Correct Answer: b

15. Objective 3: Investigate and measure the effects of increasing or decreasing the amount of energy in a physical or chemical change, and relate the kind of energy added to the motion of the particles. Looking at the picture above, which statement is true of the sidewalk? A. This is mostly likely to occur in the Summer. B. This is mostly likely to occur in the Spring. C. The city wanted to build a ramp for jumping. D. This was caused wind gusts over 50 mph. Correct Answer: a

16. Objective 3: Investigate and measure the effects of increasing or decreasing the amount of energy in a physical or chemical change, and relate the kind of energy added to the motion of the particles. Toniqua and Juan decide to do an experiment. One of them will put a drop of food coloring in hot water; the other will put a drop of food coloring in cold water. Based on your knowledge of energy and the motion of particles in a substance, predict the results of their experiment. a. The coloring will move through both containers of water at the same speed because water always has the same energy. b. The coloring will move through the cold water faster because cold water has more energy. c. The coloring will move through the hot water faster because hot water has more energy. • The coloring will float on top of the water until your put energy into it by stirring it. Correct Answer: c 

17. Objective 4: Identify the observable features of chemical reactions. Jenna suspects that she can affect the rate of the chemical change that takes place when vinegar is combined with baking soda to make her model volcano erupt at different rates. The best way for her to know for sure would be to a. ask her science teacher who does it all of the time in the laboratory at school. • experiment with several variables such as crushing, heating, stirring, cooling etc. • read about it in her textbook, under chemical reactions. • Look it up on the internet to see what Bill Nye suggests. Correct Answer: b

18. Objective 4: Identify the observable features of chemical reactions. A pile of snow melts faster than the same amount of block ice. Which factor listed below contributes the LEAST to the rate of melting? a.     surface area b.     temperature c.     exposure to direct light d.     the initial volume of snow and ice Correct Answer: d

19. Objective 4: Identify the observable features of chemical reactions. What is one way the development of synthetic fibers has affected the clothing we wear? a. synthetics are waterproof b. synthetics have more stretch c. natural fibers wear longer • synthetics don’t burn Correct Answer: b

20. Objective 4: Identify the observable features of chemical reactions. 2H2 + O2 -----> 2H2O In the equation above, which molecules are the reactants in this chemical equation? • H2 & H2O • H2O & O2 • H2 & O2 • H2 & H2O & O2 Correct Answer: c

21. Objective 4: Identify the observable features of chemical reactions. 2H2 + O2 -----> 2H2O In the balanced equation above, how many total atoms are there? • 8 • 10 • 12 • 14 Correct Answer: c

22. Objective 4: Identify the observable features of chemical reactions. 2H2 + O2 -----> 2H2O In the equation above, identify the product(s) in this chemical equation? • H2 • O2 • H2 & O2 • H2O Correct Answer: d

23. Objective 4: Identify the observable features of chemical reactions. In order for a chemical equation to be balanced, what must be true? • You must have the same number of atoms on each side only. • You must have the same number of identical atoms on each side. • You must have the same number of atoms on one side only. • You must have the same number of subscripts on each side. Correct Answer: b