Tyserium (ty) consists of two isotopes. one isotope has a mass of 331 amu and is 35.0 % abundant. the other isotope is 337 amu and is 65.0 % abundant. what is the mass of ty as it appears on the periodic table?

The atomic masses written for every element in the periodic table is the average atomic weight that is calculated from the element's isotopes. The formula would be:

Average Atomic Weight = ∑ (Isotope Mass*Relative Abundance)

Substituting the values:

Average Atomic Weight = (331 amu*0.35) + (337 amu*0.65)

Average Atomic Weight = 334.9 amu