How do autotrophs and heterotrophs benefit one another within an ecosystem?

Autotrophs are organisms which synthesis food (glucose) as product and release oxygen as by-product in the process of photosynthesis. In the process they use carbon dioxide, water in presence of sunlight. Examples of autotrophs are green plants, algae, blue green algae. The heterotrophs use glucose and oxygen produced by autotrophs. In turn, heterotrophs release carbon dioxide during cellular respiration which is used by autotrophs. In this way autotrophs and heterotrophs benefit each other.

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.