In the kinetic molecular theory of gas behavior, particles of a gas tend to move and collisions between them are select one:
a. slowly, rare
b. rapidly, rare
c. slowly, unusual
d. rapidly, elastic
e. slowly, elastic

(d) rapidly, elastic

Explanation:

In the kinetic molecular theory of gas behavior, particles of a gas tend to move rapidly and collisions between them are elastic.

Gas particles are in rapid continuous random motion colliding with themselves and the enclosing walls of the container.  When two or more gas molecules collide with each other or another body, the total kinetic energy is conserved before and after the collision. This means there is no net loss or gain of kinetic energy when particles collide. Therefore, the collisions exhibited by gas particles are completely elastic.

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