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.
The atomic mass unit is defined as: A) the mass of the hydrogen atom containing only one proton. B) the mass of electrons found in a carbon atom containing six protons and neutrons. C) 1/12 the mass of a carbon atom containing six protons and six neutrons. D) 1/14 the mass of a nitrogen atom containing 7 protons and 7 neutrons. E) none of the above