Question

How are a mole and a dozen similar?
Each represents a certain mass of material.
Each names a given number of objects.
Each identifies a specific volume.
Each measures a given number of amus.

Answer 1

Short answer: they’re alike only in one basic way — both are pure counting units. The other statements are either false for a dozen or only true for a mole under the right interpretation.

Detail:
- Each names a given number of objects — True. A dozen = 12; a mole = exactly 6.02214076×10^23 entities (Avogadro’s number).
- Each represents a certain mass of material — Not generally true for a dozen (the mass of 12 items depends on what the items are). For a mole, yes: one mole of a substance has a definite mass (its molar mass), so a given substance has a specific mass for one mole.
- Each identifies a specific volume — Not for a dozen. For a mole, only under specified conditions: one mole of an ideal gas occupies about 22.414 L at the historical STP (0 °C, 1 atm); otherwise volume depends on pressure and temperature.
- Each measures a given number of amu — No for a dozen. Yes in the sense that the mole links atomic mass units (amu) to grams: the numeric value of a particle’s mass in amu equals the mass in grams of one mole of those particles (e.g., carbon‑12 is 12 amu per atom and 1 mol of C‑12 has mass 12 g).

So the shared similarity is “both are names for fixed counts.” The other properties apply to the mole (or to both) only with the qualifications above.