This is the 18426th most frequent Russian word.
энергию
Energy.
In this sentence, the word "энергию" refers to physical energy, specifically the energy released by chemical reactions during the process of burning.
Химические реакции выделяют энергию в процессе горения.
Chemical reactions release energy during combustion.
Here, "энергию" is used metaphorically to describe the emotional or spiritual impact of nature on a person.
Я чувствую энергию природы, гуляя по лесу.
I feel the energy of nature when walking through the forest.
In this example, "энергию" refers to effort or vigor, indicating the effort required to accomplish a particular task.