Question

the image shows a representative sample of 50 atoms of a fictious element, called lemonium (le). lemonium consists of three isotopes. the red spheres are le - 19, the light blue spheres are le - 17, and the dark blue spheres are le - 15. determine the percent natural abundance of each of the three isotopes. le - 19: % le - 17: % le - 15: % tools le - 19 has an atomic mass of 19.0 u, le - 17 has an atomic mass of 17.4629 u, and le - 15 has an atomic mass of 15.7384 u. use the natural abundance and atomic mass of each isotope to determine the average atomic mass of le.

Explanation:

Step1: Count the number of each isotope

Count the red (Le - 19), light - blue (Le - 17), and dark - blue (Le - 15) spheres. Assume there are $n_{19}$ red spheres, $n_{17}$ light - blue spheres, and $n_{15}$ dark - blue spheres.

Step2: Calculate the percent natural abundance of Le - 19

Percent abundance of Le - 19=$\frac{n_{19}}{50}\times100\%$

Step3: Calculate the percent natural abundance of Le - 17

Percent abundance of Le - 17=$\frac{n_{17}}{50}\times100\%$

Step4: Calculate the percent natural abundance of Le - 15

Percent abundance of Le - 15=$\frac{n_{15}}{50}\times100\%$

Answer:

(You need to count the actual number of spheres in the image to get the specific values. For example, if there are 20 red spheres, 15 light - blue spheres, and 15 dark - blue spheres)
Le - 19: $\frac{20}{50}\times100\% = 40\%$
Le - 17: $\frac{15}{50}\times100\%=30\%$
Le - 15: $\frac{15}{50}\times100\% = 30\%$