Benzene's molecular formula is C₆H₆. To calculate its atomic mass, we need to add the atomic masses of all the atoms in the molecule:

* Carbon (C): 12.011 amu/atom * 6 atoms = 72.066 amu

* Hydrogen (H): 1.008 amu/atom * 6 atoms = 6.048 amu

Total atomic mass of benzene (C₆H₆): 72.066 amu + 6.048 amu = 78.114 amu

Therefore, the atomic mass of benzene is approximately 78.114 amu.