b The relative atomic mass of chlorine is 35.5 . What does this tell you about the relative abundance of the two naturally occurring isotopes of chlorine?

The relative atomic mass of chlorine is calculated based on the weighted average of its naturally occurring isotopes. Chlorine has two stable isotopes: 1. **^35Cl** with an atomic mass of 35. 2. **^37Cl** with an atomic mass of 37. Given the relative atomic mass of chlorine is **35.5**, we can set up the following equation to determine the relative abundances: \[ 35x + 37(1 - x) = 35.5 \] Where: - \( x \) is the fraction of **^35Cl**. - \( (1 - x) \) is the fraction of **^37Cl**. Solving for \( x \): \[ 35x + 37 - 37x = 35.5 \\ -2x = -1.5 \\ x = 0.75 \] This means: - **^35Cl** constitutes **75%** of natural chlorine. - **^37Cl** constitutes **25%** of natural chlorine. **Conclusion:** The relative atomic mass of 35.5 indicates that approximately 75% of chlorine atoms are the 35Cl isotope and about 25% are 37Cl. **Answer:** About three‑quarters of chlorine atoms are ³⁵Cl and one quarter are ³⁷Cl in nature.