* Rearrangement of atoms: Chemical reactions are essentially the breaking and forming of chemical bonds between atoms. This leads to the formation of new molecules with different properties.

* Energy change: Chemical reactions either release energy (exothermic) or require energy (endothermic) to occur. This energy change can be in the form of heat, light, or electricity.

* Change in chemical composition: The reactants, the substances that go into the reaction, are transformed into different products with different chemical formulas.

Let me know if you would like more detail on any of these points!