Chemistry test Unit 1-2 Intro to chemistry, physical and chemical properties with changes and measurements part 1. Select the correct answer. 1. Express the number 0.000042 in scientific notation. a. 4 × 10-5 b. 4.2 × 10-4 c. 0.42 × 10-4 d. 4.2 × 10-5 2. Convert 76.8 cm to m. a. 7.68 m b. 0.768 m c. 0.0768 m d. 7.68 × 10-2 m 3. Convert 2855 mg to kg. a. 0.02855 kg b. 2.855 × 10-3 kg c. 3.503 × 10-4 kg d. 0.002855 kg 4. A cube measures 2.5 cm on each edge and has a mass of 66.9 g. Calculate the density of the material that composes the cube. (The volume of a cube is equal to the edge length cubed.) a. 4.3 g/cm3 b. 10.7 g/cm3 c. 0.234 g/cm3 d. 26.7 g/cm3 5. What is the mass of 225 mL of a liquid that has a density of 0.880 g/mL? a. 0.00391 g b. 0.198 g c. 198 g d. 256 g 6. Convert 38oC to oF a. 100.4 oF b. 126 oF c. 273.15 oF d. 104 oF 7. Convert 60 K to oC a. -213.15 oC b. 333.15 oC c.-140 oC d.15.56 oC 8. Convert 156.82oC to K a. 250.28 b.116.6 c. -116.33 d. 429.97 K 9. The distance between two points is called a. Time b. Length c. Capacity d. Mass 10 The measure of how long it takes for an event to occur is called... a. b. c. d. Time Length Capacity Mass 11. Calculate the volume of the following a.20m b.200m c.240cm d.2.0cm 12. What is the volume of the ring? a. 64mL b. 78mL c. 14mL d. 60mL 13. A loaf of bread has a mass of 500 g and volume of 2500 cm3. What is the density of the bread? a. b. c. d. 0.2 g/mL 1250000 g 5 g/mL 2 g/mL 14. The density of a substance is 4.0 g/cm3. If a sample of the substance has a volume of 25 cm3, then what is its mass? a. 100 g b. 6.25 g c. 0.16 g d. 25 g 15. You have a lead ball with a mass of 420 g. The density of lead is 10.5 g/cm3. What is the volume of the ball? a. 40 cm3 b. 4410 cm3 c. 0.025 cm3 d. 42 cm3 16. Which of the following is an example of physical change? a. Mixing baking soda and vinegar together, and this causes bubbles and foam. b. A glass cup falls from the counter and shatters on the ground. c. Lighting a piece of paper on fire and the paper burns up and leaves ashes. d. Baking a birthday cake for your mother. 17. Which of the following is an example of chemical change? a. Filling up a balloon with hot air. b. Taking a glass of water and freezing it by placing it in the freezer. c. A plant collecting sunlight and turning it into food. d. Your dog ripping up your homework. 18. When a new substance is formed with different properties than the original substance it is called a a. Chemical change b. Physical change c. Freezing d. boiling 19. Which is an example of a physical change? a. Metal rusting b. Silver tarnishing c. Water boiling d. Paper burning 20. What characteristic best describes what happen during a physical change? a. Composition changes b. Composition stays the same c. Form stays the same d. Mass is lost 21. Which is an example of chemical change? a. Water freezes b. Wood is cut c. Bread is baked d. Wire is bent 22. Which is not a clue that could indicate a chemical change? a. Change in color b. Change in shape c. Change in energy d. Change in odor 23. Express 150,000,000 in scientific notation. a. 1.5 𝑥 10−8 b. 1.5 𝑥 108 c. 1.50 𝑥 106 d. 1.50 𝑥 10−6 24. Express 0.000043 in scientific notation. a. 4.3 𝑥 105 b. 4.3 𝑥 104 c. 4.3 𝑥 10−5 d. 4.3 𝑥 10−4