Rockets are an example of chemical energy being transformed because the chemical energy held in the bonds of the fuel (such as rocket propellants) is released through combustion, resulting in the production of thermal energy and gases. This release of energy creates high-pressure exhaust gases that are expelled at high velocity, generating thrust in accordance with Newton's third law of motion.
In essence, the transformation process involves the conversion of chemical energy stored in the fuel into thermal energy and kinetic energy, which allows the rocket to propel into the atmosphere.