Here's why:

* Kinetic Energy and Temperature: The temperature of a gas is directly proportional to the average kinetic energy of its particles. This means that as the temperature increases, the particles move faster, and their average kinetic energy increases.

* Kelvin Scale: The Kelvin scale is an absolute temperature scale, meaning that zero Kelvin represents the absolute absence of thermal energy. This makes it ideal for describing the relationship between temperature and kinetic energy.

Important Notes:

* Average Kinetic Energy: It's crucial to understand that we're talking about the *average* kinetic energy of the particles. Not all particles will have the same kinetic energy at a given temperature, but the average will increase with temperature.

* Other Factors: While temperature is the primary factor influencing kinetic energy, other factors can also play a role, such as the mass of the gas particles and the volume of the container.

Example:

If you double the Kelvin temperature of a gas, you double the average kinetic energy of its particles. This means they will be moving, on average, twice as fast.