Final answer:
The question seems to have a mismatch between the concept of 'chem shift' and chemical reaction types. However, chemical reactions can generally be classified as combination, decomposition, single-replacement, double-replacement, or combustion reactions.
Step-by-step explanation:
The student's inquiry seems to involve a conceptual misunderstanding, as chem shift refers to chemical shifts in nuclear magnetic resonance (NMR) spectroscopy and not to chemical reaction types. However, if the student refers to types of chemical reactions, we can classify them broadly. Here are some classifications:
Combustion reactions which commonly involve oxygen from the air and produce heat and light.
Each of these reaction types has particular patterns in how the reactants and products are structured and how they transform during a chemical reaction, which helps in predicting the outcome of a reaction when given a specific set of reactants.