15.1.2—Molar quantities where one mole of any substance is the amount containing a

One mole contains N_A≈6.02×10²³ specified particles or entities. The number is a count, not a mass.

Multiply moles by N_A to find particles, or divide particle count by N_A to find amount. State whether entities are atoms, molecules or ions.

0.50 mol of electrons contains about 3.01×10²³ electrons; 1 mol of NaCl contains that many formula units.

Avogadro’s constant is not the number of grams in a mole and does not change with substance.