The molecules of a gas are in constant random motion. This means that they have energy in what type of energy store?

The molecules of a gas are in constant random motion, which means they possess kinetic energy. Kinetic energy is the energy of motion, and in the case of gas molecules, it arises from their rapid and random movement in all directions. As these molecules collide with each other and with the walls of their container, the energy associated with their motion can be quantified using the kinetic energy formula:

$KE = \frac{1}{2}mv^2$

where $KE$ is the kinetic energy, $m$ is the mass of the molecule, and $v$ is the velocity of the molecule.

In addition to kinetic energy, gas molecules may also have potential energy, especially when considering interactions at a molecular level or in the presence of external fields. However, their constant random motion primarily signifies kinetic energy as the main energy store.

In summary, the energy associated with the molecules of a gas in constant random motion is primarily in the form of kinetic energy.