Final answer:
Gaseous molecules in an ideal gas travel in random directions until they collide with other molecules. When colliding with a rigid wall, their velocity and momentum in the x-direction are reversed. These predictions apply to ideal gases with no interactions between molecules or with the container.
Step-by-step explanation:
Gaseous molecules in an ideal gas travel in random directions until they collide with other molecules. This is due to the high speeds at which gas molecules move. These collisions cause the molecules' directions to change, but their speeds remain constant.
The direction of a gas molecule's velocity and momentum is reversed when it collides with a rigid wall in a container. This reversal occurs in the perpendicular direction to the wall, while the components of its velocity and momentum in the y- and z-directions remain unchanged.
It is important to note that these predictions about ideal gases assume perfectly elastic collisions with no interactions between molecules or with the container.