# When we say $0K$ temperature, does it mean that the energy in that system is totally zero? [closed]

When a system of particles has $T=0K$, then what is the energy configuration of the system? Is the energy of the system totally zero, or is there some energy present?

• What do you mean by "energy configuration"? Also, a "system of particles" doesn't generically have a temperature, you need to consider a statistical system that has a well-defined notion of temperature. Commented Aug 15, 2016 at 14:39
• For a system you can think of something like a Si crystal. In regards to energy configuration, I was wondering if T=0K would imply that the electrons will all have zero thermal energy, lead to them occupying the same energy states, which would be against pauli's exclusion principle because they can't occupy the same energy state, and I know that they don't. But I don't know why, i.e. why do the electrons have any thermal energy at all at T=0K Commented Aug 15, 2016 at 14:43
• Afaik the "unclear" VtC voter didn't hear from the zero-point energy until now. Commented Aug 15, 2016 at 18:18
• Possible duplicate: physics.stackexchange.com/questions/208301/… Commented Aug 16, 2016 at 2:35

The absolute amount of energy in any system is physically meaningless (unobservable). Thus, the total energy of a system at $T = 0$ K can be defined to be any value. However, changes in energy are physically meaningful. When we say a system is at absolute zero temperature, we mean that it cannot decrease its energy any further.