Lesson 3: Precipitation Reactions. A precipitation reaction is a reaction in which soluble ions in separate solutions are mixed together to form an insoluble compound that settles out of solution as a solid.That insoluble compound is called a precipitate.Solubility Rules for Ionic Compounds.esson 3: Precipitation Reactions. A precipitation reaction is a reaction in which soluble ions in separate solutions are mixed together to form an insoluble compound that settles out of solution as a solid. That insoluble compound is called a precipitate. Solubility Rules for Ionic Compounds.
The finding that extrinsic rewards can undermine intrinsic motivation has been highly controversial since it first appeared (Deci, 1971).
Intrinsic motivation has been studied since the early 1970s. 1  Intrinsic motivation is the self-desire to seek out new things and new challenges, to analyze one's capacity, to observe and to gain knowledge.