When a gas undergoes an isothermal process, there is (A) no heat added to the gas.
(B) no work done by (or on) the gas.
(C) no change in the temperature of the gas.
(D) no change in the volume of the gas.
(E) no change in the pressure of the gas.

(C) no change in the temperature of the gas.

Explanation:

isothermal process of a gas, can result to compression of the gas or expansion of the gas at a constant temperature (ΔT = 0).

For isothermal gas expansion, work is done in reducing the pressure of the gas by increasing its volume at a constant temperature. The change in the internal energy of this process is zero (ΔU = 0).

For isothermal gas compression, work is done in decreasing the volume of the gas by increasing its pressure at a constant temperature. The change in the internal energy of this process is also zero (ΔU = 0).

Therefore, when a gas undergoes an isothermal process, there is no change in the temperature of the gas.

frequency or wavelenth of em radiation in a vacuum