Which of the following best describes the energy involved in an exothermic chemical reaction before the reaction? (pick only one answer choice! ) a. the energy was stored in chemical bonds. b. the energy was created during the reaction. c. the energy was available in the environment. d. the energy was destroyed immediately during the reaction. *i'm sure that b. and d. are incorrect since energy can neither be created nor destroyed.*

Air pressure is measured in pascals. for a professional american football game, the ball should be inflated to about 90,000 pascals. scientists studied the effects of air temperature on the pressure inside american footballs by taking these steps: 1. prepare 100 footballs. 2. measure each football's air pressure. 3. divide footballs into 10 groups. 4. place the groups in different lockers cooled to different air temperatures. 5. after 12 hours, remove the footballs from lockers. 6. measure each football's pressure again. 7. compare the new pressures to the starting pressures. what two terms best describe the variable "air pressure inside the football" in this experiment? independent, qualitative independent, quantitative dependent, qualitative dependent, quantitative