The flow of energy from one trophic level to the other trophic level in a food chain is explained in the pyramid of energy.
According to the 10 percent law, 90% of captured energy is lost as heat in the previous level and only 10% is available for the next level.
At each trophic level, about 10% of the energy is transferred to the next trophic level whereas the rest is utilized for metabolic activities and lost as heat in the environment.
The chemical energy gets decreased at each stage but the total energy in the system remains the same.