In an ecosystem a population can be defimed as

In an ecosystem, a population is a group of animals that live in the same area and are the same species. For example, a herd of zebras would be a population, but a horse would not be considered apart of the population because it is a different species than the zebra. (a species are animals that can mate and produce offspring that can also mate).

the overall balanced equation

6co2 + 6h2o > c6h12o6 + 6o2

sunlight energy

where: co2 = carbon dioxide

h2o = water

light energy is required

c6h12o6 = glucose

o2 = oxygen

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.