By way of example, PPM means "components for each million". If you find out that the focus of NO2textual content NO _2NO2​ is equivalent to 1 ppm, it ensures that if you take a "sample" of air and divide it into 1,000,000 pieces, one of these will encompass NO2text NO _2NO2​.He thinks that any dilemma may be solved with the proper list of equat