Answer: The average atomic mass of X is 16.53
Explanation:
Mass of isotope X-19 = 2.282
% abundance of isotope X-19 = 12.01% = [tex]\frac{12.01}{100}=0.1201[/tex]
Mass of isotope X-21 = 18.48
% abundance of isotope X-21 = (100-12.01)% = [tex]\frac{100-12.01}{100}=0.8799[/tex]
Formula used for average atomic mass of an element :
[tex]\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}\times {{\text { fractional abundance}})[/tex]
[tex]A=\sum[(2.282\times 0.1201)+(18.48\times 0.8799)][/tex]
[tex]A=16.53[/tex]
Therefore, the average atomic mass of X is 16.53
