22. Which will react the fastest when mixed with water? A A whole Alka -Seltzer tablet B An Alka -Seltzer tablet broken into four pieces. C An Alka -Seltzer tablet broken in half. D An Alka -Seltzer crushed into a powder.
24. Cody has a piece of Aluminum, which he mixes with acid to make a reaction. How can he speed up the reaction? A Put the Aluminum in the acid in one whole piece. B Fold the Aluminum in half before he puts it in the acid. C Ball the Aluminum up into a giant ball before he puts it in the acid. D Cut the Aluminum into tiny pieces before he puts it in the acid.
26. A scientist has two samples of the same chemical: one sample is a solid block, and the other sample is a powder. The scientist puts the solid block in a beaker of water and observes a reaction. What would most likely happen if the scientist placed the powdered sample into a different beaker of water? A No reaction would occur. B A completely different reaction would occur. C The same reaction would occur but at a faster rate. D The same reaction would occur but at a slower rate.
40. Bryson burns a piece of paper, and observes that the reaction gives off heat and light. What kind of reaction is taking place? A Exothermic, because heat is released . B Endothermic, because heat is released. C Exothermic, because heat is absorbed. D Endothermic, because heat is absorbed.
42. Antoinette mixes two chemicals together in a giant beaker, and observes that the reaction gets colder as it sucks in heat from the room. What kind of reaction is this? A Exothermic, because heat is released. B Endothermic, because heat is released. C Exothermic, because heat is absorbed. D Endothermic, because heat is absorbed.
44. Terrance puts a thermometer in a jar. It reads 20ºC. Then, he adds 2 chemicals to the jar. The thermometer changes to read 25ºC as the chemical reaction occurs. a. What kind of reaction is this? A Exothermic, because heat is released . B Endothermic, because heat is released. C Exothermic, because heat is absorbed. D Endothermic, because heat is absorbed.
46. Deja puts a thermometer into a jar. It reads 30ºC. Then, she adds two chemicals to the jar. The thermometer changes to read 19ºC as the chemical reaction occurs. A. Exothermic, because heat is released. B Endothermic, because heat is released. C Exothermic, because heat is absorbed. D Endothermic, because heat is absorbed.
62. What would you use to transfer electrical energy from a power plant to your house? A. metalbecause it has a high resistanceb. nonmetal because it has high resistancec. nonmetal because it has low resistance d. metal because it has a low resistance
64. What would you use to insulate (put around to keep safe) an electrical wire? A. metalbecause it has a high resistance b. nonmetal because it has high resistance c. nonmetal because it has low resistance d. metal because it has a low resistance
75. You are correct. You may continue. Remember the number on top is the atomic number that tells you the number of protons and electrons. The number of protons is always the same number as the number of electrons.
