A radioisotope is found to decrease from 3.600 x 1024 radioactive atoms to 1.125 x 1023 radioactive atoms in 80,000 years.
What is the radioisotope's Half-Life?
time would it take for 252 ram samnle of Technetium-99 (half life = 2.13 x 105

Acertain atom has 22 protons and 19 electrons. this atom loses an electron. the net charge on the atom is now 4+1+01-4-. if this same atom with 22 protons and 19 electrons were to gain 3 electrons, the net charge on the atom would be 3+2+02-3-.