Her behavior has been reinforced (i.e. strengthened). Reinforcement can be external or internal and can be positive or negative. If a child wants approval from parents or peers, this approval is an external reinforcement, but feeling happy about being approved of is an internal reinforcement.
It remained to define the unit of amount of substance by fixing the corresponding mass of carbon 12; by international agreement, this mass has been fixed at 0.012 kg, and the unit of the quantity amount of substance was given the name mole (symbol mol).
The mole (abbreviation, mol) is the Standard International ( SI ) unit of material quantity. One mole is the number of atom s in precisely 12 thousandths of a kilogram (0.012 kg) of C-12, the most common naturally-occurring isotope of the element carbon. This number is equal to approximately 6.022169 x 10 23 , and is also called the Avogadro constant. The mole is the only fundamental SI unit that is dimensionless. That means it represents a simple numerical quantity or value; it is a term similar in nature to dozen (meaning 12) or gross (meaning 144). But 1 mol is, unlike a dozen or a gross, an incomprehensibly large number.