Question

naturally occurring thallium is composed mainly of two isotopes. tl - 203 and tl - 205. the average atomic mass of thallium is 204.38 u. which pie chart best shows the relative abundances of the two isotopes in nature? choose 1 answer: a tl - 203 tl - 205 b tl - 203 tl - 205 c tl - 203 tl - 205

Explanation:

Step1: Calculate the difference between average atomic mass and each isotope's mass

The average atomic mass of thallium is \(204.38\ u\).
For \(Tl - 203\): \(204.38-203 = 1.38\)
For \(Tl - 205\): \(205 - 204.38=0.62\)

Step2: Analyze the relationship between difference and abundance

The isotope with a mass closer to the average atomic mass has a higher abundance. Since \(204.38\) is closer to \(205\) (\(0.62<1.38\)), \(Tl - 205\) has a higher abundance than \(Tl - 203\).

Answer:

A.