At sea level, there are approximately 2.6 × 1025 molecules m-3 of the atmosphere.
One of the gases making up the atmosphere has a concentration of 3.90 × 1021 molecules m-3. What is the concentration of this gas expressed in parts per million (ppm)?
The Attempt at a Solution
totally flumoxed once again lol
2.6x1025 - 3.90x1021 = 2.59961x1025
now the answer is wrong, what i have done is wrong and to get the right answer in ppm is completely going over my head for some stupid reason.