The air exhaled from the lungs of a smoker has a concentration of 24 ppm CO. Express the concentration as a percent.

Answer;

0.0024%

Explanation; Parts per million or ppm means out of a million. Usually describes the concentration of something in water or soil. One ppm is equivalent to 1 milligram of something per liter of water (mg/l) or 1 milligram of something per kilogram soil (mg/kg).

Therefore to convert 24 ppm of CO as a percentage.

24 ppm * 100%

(24/10⁶) * 100%

= 0.0024%