One mole of carbon atoms has a smaller mass than one mole of sulfur atoms because carbon atoms are lighter than sulfur atoms.

Here's why:

* Atomic Mass: The atomic mass of an element is the average mass of its atoms, measured in atomic mass units (amu). Carbon has an atomic mass of approximately 12 amu, while sulfur has an atomic mass of approximately 32 amu.

* Moles: A mole is a unit of measurement that represents a specific number of particles (6.022 x 10^23, known as Avogadro's number). One mole of any element contains the same number of atoms.

* Mass of a Mole: Since sulfur atoms are heavier than carbon atoms, one mole of sulfur atoms will have a greater mass than one mole of carbon atoms.

In simpler terms: Imagine you have a bag full of marbles. If some marbles are made of a heavier material, the bag of heavier marbles will weigh more, even if both bags contain the same number of marbles.