5.2.1 NumAtoms, NumBonds

The ``NumAtoms'' method returns the number of atoms in the molecule, and the ``NumBonds'' method returns the number of bonds in a molecule. Note that these methods return the number of ``explicit'' atoms and ``explicit'' bonds of a molecule, and don't include any ``implicit'' hydrogens (or bonds to them). For more details, see the section on ``implicit vs. explicit hydrogen atoms''.