The mass of one lead atom is 3.440639294e-22 grams. This is a conversion from the standard atomic weight of lead, which is 207.2 atomic mass units.
The mass of each element in atomic mass units, sometimes called the atomic weight, is listed in the periodic table of elements, which is used by scientists to classify elements and study relationships between elements. The atomic weight is close to the number of protons and neutrons in the atom because electrons have very little mass. Lead, abbreviated Pb, is element number 82 with the corresponding atomic weight of 207.2. This is converted to grams using the constant 6.0221419828e+23. Thirty-six elements are heavier than lead, and ununoctium is the heaviest element.