Acid rain occurs over the northeastern United States largely because of the production of ozone in the atmosphere.
sulfur oxide and sulfuric acid from burning coal.
carbon dioxide from plants.
carbon monoxide from automobile exhaust.

sulfur oxide and sulfuric acid from burning coal.

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.

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem