What does the internal energy of an ideal gas depend on?

The internal energy of an ideal gas is primarily dependent on its temperature. In thermodynamics, the internal energy is associated with the kinetic energy of the gas particles, which is largely influenced by how fast these particles are moving. As temperature increases, the average kinetic energy of the gas molecules also increases, leading to a higher internal energy.

For an ideal gas, the relationship between internal energy and temperature is direct, meaning that any change in temperature will result in a change in internal energy. The other options—volume, pressure, and mass—do not have a direct influence on the internal energy of an ideal gas in the same straightforward manner. While changes in volume and pressure can affect how gas behaves in terms of its state, they do not independently alter the internal energy without a corresponding change in temperature. Additionally, for an ideal gas, internal energy is typically simplified to depend only on temperature and the amount of gas (which relates to mass); however, it’s the temperature that dictates the absolute internal energy level.