how internal energy is a state function??

Solution -

Internal energy is regarded as a state function as it is independent of the path followed for the change of the state of the system.

It is the total energy of a system which is made up of many components for example, translational kinetic energy of molecules, bond energy, electronic energy, and the intermolecular interaction energy of the constituents’ particles of the system.

Also, internal energy is known as a function of pressure, volume, temperature, etc., and all of these variables are called state functions.
Internal energy is independent of the path used to get from one condition to the next. It depends on the system’s current state.
Internal energy does not depend on the path used to go from initial state to final state, but it depends on state. Internal energy of a system is an extensive property.