ABSTRACT
In order to understand this question, we first need to understand what we mean by energy. Originally, the word energy comes from the Greek word energeia which is translated as activity and indeed life is certainly some sort of activity. In daily life too, we clearly link activity with energy. Have you ever said “Today I feel really energetic!” to indicate your belief that you can achieve lot, or in other words that you can do or move a lot? In the scientific context it therefore comes natural to ask “How much energy does something have?” or “How much energy does it take to do this?”
