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 is thermodynamic process in which temperature is constant, that is there is no change in temperature of the gas. Since there is a constant temperature , the change in the internal energy is zero.

ΔU = 0, in Isothermal process (constant temperature).

c. no change in the temperature of the gas

this is poiselle's equation from fluid mechanic in physics. mech eng