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).
What is the mole concept? The mole concept is in chemistry used to calculate the quantity or amount of chemical substances that are used and produced in a chemical reaction. There are various words in English that are associated with various quantities as show by the table below.