As the temperature of a closed system approaches absolute zero, - a the molecules of the system gain energy. b the number of molecules of the system increases. c the energy of the molecules increases. d the motion of the molecules decreases.

Option (D) is correct.

Explanation:

The velocity of gas molecules is given by

V=

R= universal gas constant=8.314 J/K mole

T= Temperature in kelvin

m= molar mass of gas

As the temperature approaches absolute zero,the rms velocity of the gas decreases and thus the motion of the molecules decreases. At T= 0 K, V=0. So at absolute zero, the molecular motion ceases altogether.

Thus the motion of the molecules decreases as the temperature approaches absolute zero.

a) electrical > light, sound, and thermal< < < <

) the mechanical energy of the firefighter moving.< < < < a) electrical > light, sound, and thermal< < < <

c) both a and b.