Isothermal

[Jason Yan]

Having reference to the geographical distribution of
temperature, as exhibited by means of isotherms; as, an isothermal
line; an isothermal chart.

[Tjalfdyed 0]

of a process or change taking place at constant temperature

[Kai]

Of or pertaining to an isotherm

[LeeTot 0]

In thermodynamics, an isothermal process is a type of thermodynamic process in which the temperature T of a system remains constant: ΔT = 0. This typically occurs when a system is in contact with an outside thermal reservoir, and a change in the system occurs slowly enough to allow the system to be continuously adjusted to the temperature of the reservoir through heat exchange (see quasi-equilibrium). In contrast, an adiabatic process is where a system exchanges no heat with its surroundings (Q = 0).
Simply, we can say that in an isothermal process

T

constant

{\displaystyle T={\text{constant}}}

Δ
T

0

{\displaystyle \Delta T=0}

d
T

0

{\displaystyle dT=0}

For ideal gases only, internal energy

Δ
U

0

{\displaystyle \Delta U=0}
while in adiabatic processes:

[GrokLuth 0]

ī-so-thėr′mal, adj. having an equal degree of heat.—n. I′sotherm, an imaginary line connecting places on the earth which have the same mean annual temperature. [Fr. isotherme—Gr. isos, equal, thermē, heat—thermos, hot.]