The trachea, bronchi and bronchioles form the tracheobronchial tree â a system of airways that allow passage of air into the lungs, where gas exchange occurs.he trachea marks the beginning of the tracheobronchial tree. It arises at the lower border of cricoid cartilage in the neck, as a continuation of the larynx. By Bibi Saint-Pol [CC BY-SA 3.0], via Wikimedia Commons. Fig 1.0 â Overview of the tracheobronchial tree.
While relative masses are nice if you want to compare protons, neutrons and electrons to one another, it doesn't tell you what the actual masses of these particles are. In kilograms, the masses are: Neutron = 1.6749286*10-27 kg.
Assuming that the neutron mass was close to that of the proton, Chadwick bombarded hydrogen atoms with his produced neutrons to learn the speed of the protons after the collisions. Then setting the neutron speed equal to those proton speeds, he used the above energy expression to get a neutron mass of 938 +/- 1.8 MeV.