You decide it is time to clean your pool since summer is quickly approaching. your pool maintenance guide specifies that the chlorine, cl 2, the concentration of the pool should be between 1 and 3 ppm. in order to determine if your pool is safe to swim in, you send a sample of pool water to a chemist for analysis of the cl 2 content. the chemist reports a chlorine concentration of 4.23 × 10 − 5 m. convert the concentration of cl 2 to parts per million ( ppm ).