Final answer:
The number of particles in a substance is directly proportional to the number of moles as a mole represents Avogadro's number of particles. Mass in grams must be converted to moles based on the molar mass to relate to the number of particles.
Step-by-step explanation:
The number of particles in a substance is directly proportional to the number of moles of the substance, not the grams of the substance. This is because a mole represents a fixed number of particles: Avogadro's number, which is 6.02 × 10²³ particles. The mass in grams of one mole of a substance is equal to its molecular or atomic mass in unified atomic mass units (u).
For conversions between mass and number of particles, the process will always involve conversion to and from moles. To convert from the mass of a substance to the number of particles, you would first divide the mass by the molar mass to determine the number of moles, and then multiply by Avogadro's number to find the number of particles.
Comparatively, when dealing with mass directly, it is not proportional to the number of particles due to differences in the density and the molar mass of substances. Therefore, you cannot directly convert grams to particles without considering the substance's molar mass to find out the moles involved.