Internal Energy

Internal Energy


Definition#1:"The total energy contained in a system is called internal energy".

Definition of internal energy

Definition#2:"The sum of kinetic and potential energies of the particles is called internal energy".

Definition of internal energy


Symbol:It is denoted by U.


Explanation:A number of components contribute towards the internal energy of a system, which are;

1)Translational kinetic energy

2)Rotational kinetic energy

3)Vibrational kinetic energy

4)Bond Energy

5)Electronic Energy

6)Potential Energy due to attraction 


Characteristics: Following are the characteristics of internal energy:

1)Internal energy cannot be measured, but change in internal energy can be measured.

2)Internal energy is an extensive property, depending upon the quantity of substance.

3)Internal energy is a state function depending upon initial and final state of the system and independent of path.

4)Change in internal energy for cyclic process is zero.