Many types of epithelial cells perform the function of

secretion

Explanation:

Epithelial cells are juxtaposed, polyhedral cells with much cytoplasm, developed cytoskeleton and polarity. They are juxtaposed due to the presence of cell junctions and little extracellular matrix. The abundance of cytoplasm in this type of cell is related to the intense biochemical activity. These cells perform various metabolic processes such as synthesis and secretion.

For this reason, we can state that many types of epithelial cells perform the function of secretion.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.