Convert 0.75 ug/g to the ppb scale
The correct answer and explanation is :
To convert 0.75 micrograms per gram (µg/g) to the parts per billion (ppb) scale, you can follow these steps:
Step 1: Understand the relationship between µg/g and ppb
1 µg/g is equivalent to 1 ppb.
This is because:
- 1 gram (g) = 1,000,000,000 nanograms (ng), and
- 1 microgram (µg) = 1,000 nanograms (ng).
Therefore, 1 µg/g = 1,000 ng / 1,000,000,000 ng = 1 ppb. This means that the units of µg/g and ppb are equivalent when considering concentrations.
Step 2: Apply the conversion factor
Given the concentration 0.75 µg/g, and knowing that 1 µg/g equals 1 ppb:
[
0.75 \, \mu g/g = 0.75 \, ppb
]
Step 3: Interpretation of the result
Thus, 0.75 µg/g is directly equivalent to 0.75 parts per billion (ppb). This means that in a sample, there are 0.75 parts of the substance in every billion parts of the sample.
Why does this work?
To elaborate further, both µg/g and ppb express concentrations of substances in very small amounts. Parts per billion (ppb) is commonly used to express very dilute concentrations in water, air, or soil samples. Since both µg/g and ppb express the ratio of mass of a solute to the mass of the solvent or medium, the values are numerically equivalent.
Conclusion
The conversion of 0.75 µg/g to the ppb scale results in 0.75 ppb. The reason the conversion is straightforward is that both units represent the same scale, just in different terms of mass per volume or mass per mass. Therefore, 0.75 µg/g = 0.75 ppb.