The Kinetic Molecular Theory, or KMT, helps us understand how gases act. But it doesn’t always explain everything, especially when things get really cold. Here are the main ideas:

1. Assumptions of KMT:

   • Gas particles are always moving around randomly.
   • When they bump into each other, they don't lose energy; this is called elastic collision.
   • The space taken up by gas particles is very small compared to the whole gas.

2. Real Gas Behavior at Low Temperatures:

   • When it's cold, gas behavior changes because the forces between particles start to matter more.
   • The van der Waals equation is one way to make adjustments for these changes, showing that real gases don’t always act like we expect.

3. Critical Temperature:

   • There’s a specific temperature below which gases turn into liquids.
   • For example, noble gases like helium have a critical temperature of about 5.2 Kelvin. Below this temperature, helium’s behavior doesn’t follow KMT predictions anymore.

4. Statistical Data:

   • When temperatures drop below 273 Kelvin, the pressure and volume of real gases decrease more than 20% from what we would expect in an ideal gas.

In short, while KMT is a helpful way to think about gases, it has its limits, especially when it gets cold!