The internal energy of a system is always increased by .

The options are

A) adding heat to the system

B) having the system do work on the surroundings

C) withdrawing heat from the system

D) adding heat to the system and having the system do work on the surroundings

E) a volume compression

The answer is

A) adding heat to the system

Explanation:

It is important to note that increase in temperature will result in the collision of more particles thereby resulting in a corresponding increase in the internal energy of the system.

The relationship between temperature and internal energy is a direct one. As temperature increases, internal energy also increases and vice versa.

Doing thermodynamic work on the system

Explanation:

The internal energy of a system can be increased by introduction of matter, by heat, or by doing thermodynamic work on the system. ... If the containing walls pass neither matter nor energy, the system is said to be isolated and its internal energy cannot change.

Internal energy is NOT all the energy in the system, it is the kinetic and potential energy associated with the random motion of the molecules of an object. If you heat an object, you will increase its internal energy. As the object cools, its internal energy will decrease.

The internal energy can be changed by changing the temperature or volume of the object without changing the amount of particles in the object. Temperature: If the temperature of a system rises, the molecules will travel quicker, therefore have more kinetic energy and so the Internal Energy will increase.