Percentage abundance is a way to express the relative proportions of different isotopes of an element in a sample or the relative amounts of different elements in a mixture. It is commonly used in chemistry, geology, and environmental science.
To calculate the percentage abundance of an isotope, you use the following formula:
\[ \text{Percentage Abundance} = \left( \frac{\text{Number of atoms of the isotope}}{\text{Total number of atoms of all isotopes}} \right) \times 100% \]
For example, if an element has two isotopes, A and B, and you have a sample that contains 70 atoms of isotope A and 30 atoms of isotope B, you would calculate the percentage abundance of each isotope as follows:
- Total number of atoms = 70 (A) + 30 (B) = 100
- Percentage abundance of A = (70 / 100) × 100% = 70%
- Percentage abundance of B = (30 / 100) × 100% = 30%
This concept is not only applicable to isotopes but can also be extended to mixtures of elements or compounds, where the total abundances of each component can be expressed as a percentage of the total mixture.