unknown element is a mixture of isotopes ¹²⁰X and ¹²²X. The average atomic mass of X is 120.81 amu. What is the percent abundance of ¹²²X?
- busterwasmycatLv 71 month ago
approximately 40 %. Simple mass balance equation. The presumption that isotope 120X has a mass of 120 AMU, and that 122X has a mass of 122 AMU, is, of course, likely untrue. Only 12C has an actual mass of 12 AMU, and that is because we define AMU that way.
- az_lenderLv 71 month ago
122*x + 120*(1-x) = 120.81 =>
2x = 0.81 =>
x = 0.405 = 40.5%