Respuesta :
Answer: The percent abundance of Ne-21 isotope is 0.27 %
Explanation:
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:
[tex]\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i[/tex] .....(1)
Let the fractional abundance of Ne-21 isotope be x
- For isotope 1 (Ne-20) :
Mass of isotope 1 = 20 amu
Percentage abundance of isotope 1 = 90.48 %
Fractional abundance of isotope 1 = 0.9048
- For isotope 2 (Ne-21) :
Mass of isotope 2 = 21 amu
Fractional abundance of isotope 2 = x
- For isotope 3 (Ne-22) :
Mass of isotope 3 = 22 amu
Percentage abundance of isotope 3 = 9.25 %
Fractional abundance of isotope 3 = 0.0925
Average atomic mass of neon = 20.18 amu
Putting values in equation 1, we get:
[tex]20.18=[(20\times 0.9048)+(21\times x)+(22\times 0.0925)][/tex]
x = 0.0027
Percentage abundance of Ne-21 isotope = [tex](0.0027\times 100)=0.27\%[/tex]
Hence, the percent abundance of Ne-21 isotope is 0.27 %
