Solution. 1  This species has a 2â charge on it, so it is an anion. Anions are named using the stem of the element name with the suffix -ide added. 2  Because this species has no charge, it is an atom in its elemental form. This is cobalt. 3  In this case, there is a 2+ charge on the atom, so it is a cation.
1. 2. 3. The walls of the alveoli are composed of a single layer of flattened epithelial cells, as are the walls of the capillaries, so gases need to diffuse through just two thin cells. The alveoli walls are kept moist by water diffusing from the surrounding cells.he walls of the alveoli are composed of a single layer of flattened epithelial cells, as are the walls of the capillaries, so gases need to diffuse through just two thin cells. The alveoli walls are kept moist by water diffusing from the surrounding cells.
Alveoli. The epithelium of the alveoli, contains two main types of cells: 1. type I pneumocytes: large flattened cells - (95% of the total alveolar area) which present a very thin diffusion barrier for gases.They are connected to each other by tight junctions.2. type II pneumocytes (making up 5% of the total alveolar area, but 60% of total number of cells).lveoli. The epithelium of the alveoli, contains two main types of cells: 1. type I pneumocytes: large flattened cells - (95% of the total alveolar area) which present a very thin diffusion barrier for gases.