The Laws of Chemical Combination describe the basic principles obeyed by interacting atoms and molecules, interactions that can include many different combinations that happen in many different ways. This amazing diversity of interactions allows for an astounding variety of chemical reactions and compounds. Spontaneous chemical reactions happen constantly, shaping the world around us, while humans engineer specific reactions to our benefit and attempt to curb reactions that hurt us. Though chemical reactions can be as complex as they are numerous, they are all fundamentally governed by these same guiding Laws of Chemical Combination, which lay the groundwork for analysis of chemical reactions.