Which statement is true about concentration units?

Which statement is true about concentration units?

• A. 1% equals 1,000 ppm
• B. 1% equals 5,000 ppm
• C. 1% equals 20,000 ppm
• D. 1% equals 10,000 ppm

Answer: (D)

Concentrations are often shown as a percent or as parts per million (ppm), and the two units are related by a simple scale. Percent means per hundred, while ppm means per million. To convert 1% to ppm, convert the percent to a decimal (1% = 0.01) and multiply by 1,000,000. 0.01 × 1,000,000 = 10,000, so 1% equals 10,000 ppm. That’s why the statement stating 1% equals 10,000 ppm is true. This helps when reading results in either unit: 1% is the same concentration as 10,000 ppm, 0.5% equals 5,000 ppm, and so on, which is handy in environmental measurements like those in the EPA Lead Supervisor course.

Concentrations are often shown as a percent or as parts per million (ppm), and the two units are related by a simple scale. Percent means per hundred, while ppm means per million. To convert 1% to ppm, convert the percent to a decimal (1% = 0.01) and multiply by 1,000,000. 0.01 × 1,000,000 = 10,000, so 1% equals 10,000 ppm. That’s why the statement stating 1% equals 10,000 ppm is true. This helps when reading results in either unit: 1% is the same concentration as 10,000 ppm, 0.5% equals 5,000 ppm, and so on, which is handy in environmental measurements like those in the EPA Lead Supervisor course.