posted by Gigi .
Lead has four stable isotopes. ^204Pb (1.4%), ^206Pb (24.1%). ^207Pb (22.1%) and ^208Pb (52.4%). Find the atomic mass of ^208 Pb given that ^204Pb has an atomic mass of 203.973 amu, ^206Pb has an atomic mass of 205.974 amu, and ^207Pb has an atomic mass of 206.976 amu.
atomicmass=Sum of massIsotopes*decimalPercent