What is the mean free path of a N molecule in an ultra-high-vacuum chamber at a pressure of 1.0x10-5Pa and temperature of 400 K? Take the diameter of a Ny molecule to be 0.36 nm and note 1 nm =10 m. In an ultra-high-vacuum chamber, the number density n is extremely low. The molecules have very low chance bumping into each other, therefore the mean free path is rather long Answer in units of m and round to the nearest integer Hints The formula for the mean free path is A= kBT 2po In the formula, or is the collision cross-section and a = nd. Make the appropriate unit conversions. Expect the answer in the hundreds to the thousands as the mean free path is rather long in an ultra-high-vacuum chamber.