Answer: The average atomic mass of this element is 428.68 .
Explanation:
Average atomic mass = [tex]\sum _{i=1}^n(\text{Atomic mass of an isotope})_i(\text{fractional abundance of an isotope})_i[/tex]
Atomic mass of Swidorskium-428 = 428
Abundance of Swidorskium-428 = 86.4%=0.864
Atomic mass of Swidorskium-433. = 433
Abundance of Swidorskium-433 = 13.6= 0.136
The atomic mass of the element is
= (atomic mass of Swidorskium-428 )(abundance) + (atomic mass of Swidorskium-433)(abundance)
The atomic mass of Swidorskium = (428)(0.864)+(433)(0.136) = 428.68
