What net charge would you place on a 100-g piece of sulfur if you put an extra electron on 1 in 1012 of its atoms? (Sulfur has an atomic mass of 32.1 u. Atomic Mass Unit = 1.660×10-27 kg/u Negative charge of an electron = 1.602×10-19 C 30 micro Coulomb 20 micro Coulomb 90 micro Coulomb 60 micro Coulomb