How do gas molecules move?

Gas molecules move constantly and randomly due to their high energy levels and the large amount of space between them. This random motion occurs in all directions and varies in speed, leading to a distribution of energies among the particles. The concept of random motion in gases is fundamental to the kinetic molecular theory, which describes how gas particles collide with one another and with the walls of their container, creating pressure.

In contrast, the other options imply more restricted or uniform patterns of movement. Gas molecules do not only move in a straight line; rather, they travel in all directions and can change their trajectory upon collision with other molecules. Circular motion is not typical for gas molecules, as they do not have a fixed path and their movement is influenced by collisions. Lastly, gas molecules do not move slowly and methodically; they are typically very fast and exhibit a broad range of velocities depending on the temperature, making them far from methodical in their motion. These characteristics of movement are what underlie many gas laws and behaviors observed in practical scenarios.