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 Number of an element is always equal to the number of protons. The Mass Number of an element is equal to the protons added to the neutrons. The element Sodium has an atomic number of 11 and an average atomic mass of 22.98 which makes the mass number 23. Therefore. An atomic number of 11 means this atom will have 11 protons. A mass number of 23 means 23 - 11 this atom will have 12 neutrons. Since this atom is neutral the positive protons must be equal to the negative electrons. This atom will have 11 electrons.