An atom of lead (Pb) having an atomic mass of 207 amu has an atomic number of 82. How many neutrons are present in this atom of lead?
Record your answer in the space provided.
125 neutrons.
To find the number of neutrons in an atom, you subtract the atomic number from the atomic mass. In this case, 207 (atomic mass) - 82 (atomic number) = 125 neutrons.