We cannot see an atom with our vision, but we will look at models of an atom in this course to help us understand. These molecules are in constant motion. As they move they bump into walls and into one another. When they run into one another they don t stick but bounce off of each other. See answer to 15 17.
Gases exert pressure by the molecules bouncing off the sides of the container.
The more times they bounce off the sides, the higher the pressure. A measure of how hot or cold an object is. Heat is a measure of the total energy content of a sample, which includes heat content and temperature. No temperature lies below this point. The difference between the two scales is that they differ by 273 degrees.