Question: Calculate the mass in grams of a single carbon (C) atom.
To calculate the mass of a single atom, first look up the atomic mass for carbon from the Periodic Table.
This number, 12.01, is the mass in grams of one mole of carbon. One mole of carbon is 6.022 x 1023 atoms of carbon (Avogadro's number). This relation is then used to 'convert' a carbon atom to grams by the ratio:
mass of 1 atom / 1 atom = mass of a mole of atoms / 6.022 x 1023 atoms
Solve for mass of 1 atom
mass of 1 atom = mass of a mole of atoms / 6.022 x 1023
mass of 1 C atom = 12.01 g / 6.022 x 1023 C atoms
mass of 1 C atom = 1.994 x 10-23 g
The mass of a single carbon atom is 1.994 x 10-23 g .