The hypothetical element Supposium exists in four isotopic forms. The relative masses and percentage abundances for these for isotopes are, respectively: 12.0amu and 27.3%, 15.0 amu and 31.3%, 13.0amu and 13.7%, and 17.amu and 27.7%. What is the atomic mass of Supposium? (sig. figs count here)

To find the atomic mass of Supposium, we need to calculate the weighted average of the isotopic masses based on their percentage abundances.

First, we multiply the mass of each isotope by its percentage abundance:
(12.0 amu)(0.273) = 3.276 amu
(15.0 amu)(0.313) = 4.695 amu
(13.0 amu)(0.137) = 1.781 amu
(17.0 amu)(0.277) = 4.709 amu

Next, we add up the weighted masses:
3.276 amu + 4.695 amu + 1.781 amu + 4.709 amu = 14.461 amu

Therefore, the atomic mass of Supposium is 14.461 amu.