Respuesta :
Answer : The mass of nitrogen-15 is, 15.1 amu
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)
For [tex]^{14}\textrm{N}[/tex] isotope:
Mass of [tex]^{14}\textrm{N}[/tex] isotope = 14.0 amu
Fractional abundance of [tex]^{14}\textrm{N}[/tex] isotope = 99.6 % = 0.996
For [tex]^{15}\textrm{N}[/tex] isotope:
Mass of [tex]^{15}\textrm{N}[/tex] isotope = ?
Fractional abundance of [tex]^{15}\textrm{N}[/tex] isotope = 0.370 % = 0.00370
Average atomic mass of nitrogen = 14.0 amu
Now put all the given values in equation 1, we get:
[tex]14.0=[(14.0\times 0.996)+(\text{Atomic mass of }^{15}\textrm{N}\times 0.00370)][/tex]
[tex]\text{Atomic mass of }^{15}\textrm{N}=15.1amu[/tex]
Therefore, the mass of nitrogen-15 is, 15.1 amu
