A sample is taken that has 400,000,000 particles in it. If 20 of these particles are a dangerous chemical, what is the concentration of this chemical in parts-per-million (ppm)?
20 parts in 400 million would be 10 parts in 200 million or 1 part in 20 million or 1/20 part in 1 million or 0.05 ppm.
(20*1,000,000/400,000,000) = 0.05 ppm
To find the concentration of a chemical in parts-per-million (ppm), we need to divide the number of particles of the chemical by the total number of particles in the sample and then multiply by one million.
In this case, we have 20 particles of the dangerous chemical and a total of 400,000,000 particles in the sample.
The concentration in ppm can be calculated using the following formula:
Concentration (ppm) = (Number of particles of the chemical / Total number of particles) x 1,000,000
Substituting the given values:
Concentration (ppm) = (20 / 400,000,000) x 1,000,000
Now, let's calculate it step by step:
Step 1: Divide 20 by 400,000,000:
20 / 400,000,000 = 0.00000005
Step 2: Multiply the result by 1,000,000:
0.00000005 x 1,000,000 = 0.05
Therefore, the concentration of the dangerous chemical in the sample is 0.05 parts-per-million (ppm).