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.
Many molecules can pass freely across cellular membranes. Small molecules and nonpolar molecules are the ones that can move most easily across the lipid bilayer and enter the cell. Diffusion is the process that causes these molecules to move in or out of the cell.any molecules can pass freely across cellular membranes. Small molecules and nonpolar molecules are the ones that can move most easily across the lipid bilayer and enter the cell. Diffusion is the process that causes these molecules to move in or out of the cell.