[Zohaib]

What does one mole of a substance represent on a microscopic, atomic basis? What does one mole of a substance represent on a macroscopic. mass basis?

6.02 x 10^23, is that the answer, wouldn't their be two answers?

[Yggdrasil]

Probably for the microscopic basis, 6.02x10²³ particles is a good answer.  However, for the macroscopic basis, think about what the mass of a mole of a particular substance will be.

[Zohaib]

so the answer would be 6.02 x 10^23 and then the other one would just be the mass of any given element? Wait. so i'd to avogadros number times the mass of any element?

[Yggdrasil]

Basically Avogadro's number is the conversion factor from atomic mass units (daltons) to grams:  6.02x10²³ amu = 1g.  Therefore, if you have a mole of oxygen atoms each weighing 16 amu each, the mass will be (6.02x10²³ x 16) amu.  If you apply the conversion factor, you get:

(6.02x10²³ x 16) amu x (1 g/6.02x10²³ amu) = 16 g

This is why the mass in grams of a mole of a particular element is equal to that element's atomic weight.