Are those considered theories?

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.

potentially fatal issues such as heart attacks and strokes

explanation:

it can affect the plants by how hot or cold the temperature

explanation:

it can affect the plants by how hot or cold the temperature is and the amount of precipitation can affect the plants cause it needs to have reasonable amount