20. In the previous combustion experiment, the technician determined that the mass of the firewood and oxygen reactants before burning was 2.72 kg, and the mass
of the cooled ash that remained after burning was 0.095 kg.
During that combustion experiment, the temperature inside the burning chamber
was extremely hot, and the temperature on the outside of the chamber was also
extremely hot. The technician was careful not to place his hands on the outside
surface of the chamber during the combustion experiment to avoid getting
burned. Is this burning chamber an example of an open system, a closed system,
or an isolated system? Explain your answer.