Heat that flows by conduction is the transfer of thermal energy between substances in contact. What must occur for this to happen? The two systems must be the same temperature.
The two systems must not be touching each another.
One system must have higher kinetic energy than the other system.
The thermal energy of one system must be the same as the thermal energy of the other system.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.

answer: cellular respiration takes in food and uses it to create atp, a chemical which the cell uses for energy. usually, this process uses oxygen, and is called aerobic respiration. it has four stages known as glycolysis, link reaction, the krebs cycle, and the electron transport chain.