The maximum number of individuals that can exist in an environment is the Max growth rate
Max population
Carrying capacity
Growth capacity

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

not sure if this is what you'r looking for eubacteria and archaebacteria

meiosis is the correct answer