Difference between atoms, molecules, and formula units [ENDORSED]

[Irene Kang 3F]

Is the only difference between atoms, molecules, and formula units that atoms are the units for elements, molecules for molecular compounds, and formula units for ionic compounds? Also, whenever we need to find them we can just use Avogadro's number for all of these right?

[Jeffrey J Cheng 2L]

Yes, I think that is correct. Whenever you want to convert moles of anything to the number of the same thing, you can multiply by Avogadro's number.

[Allison Peng 1D]

I believe they all basically refer to the same thing as single units of the atom/molecule/ionic compound, and using Avogadro's number can convert all of them to the number of moles.

[Isabelle Kim 3E]

Yup, you're right about using the Avogadro's constant whenever you convert from # of moles to a # of atoms and vice versa. And you'd always use the Avogadro's constant for everything. I always try to keep track of the units that I want to get rid of as I'm doing these types of conversion.

[Mark_Botros_1D]

I believe that is also correct. Avagadro's number can be used for all of them as well.

[AudreyQian1J]

I believe the replies are correct as well. An atom contains a single nucleus and is the fundamental unit of an element, such as C and Ne. Molecules consist of at least two atoms bonded together by valence forces. Formula units are like empirical formulas for ionic compounds (Ex. NaCl). Avogadro's number is the number of units per mole, and I believe it can be used to switch from moles to atoms, ions, molecules, and formula units, and vice versa.