1) compounds may be represented by chemical formulas. in the chemical formula for water which is h20, the 2 which represents the number of hydrogen atoms is called a) the reactant. b) the subscript. c) the coefficient. d) the atom factor. 2) carbon dioxide can be represented by the chemical formula a) c2o b) co2 c) ca2o d) cao2 3) as a roller coaster goes downhill a) kinetic energy is converted into potential energy. b) potential energy is converted into kinetic energy. c) electrical energy is converted into potential energy. d) potential energy is converted into electrical energy. 4) which of these would have the greatest potential energy? a) a roller coaster at the top of a hill. b) a roller coaster half-way up the hill. c) a roller coaster half-way down the hill. d) a roller coaster at the bottom of the hill. an object that has kinetic energy must be a) at rest. b) stopped. c) in motion. d) at an elevated position. 7) which represents potential energy? a) bread baking b) lawnmower cutting grass c) car racing downhill d) weed whacker full of gas 8) a skateboarder is standing at the top of a tall ramp waiting to begin a trip. the skateboarder has a) kinetic energy only. b) potential energy only. c) both kinetic and potential energy. d) neither kinetic or potential energy. 9) which of these is not a mixture? a) baking soda b) salt and water c) iron filings and sand d) metal paper clips and plastic paper clips