All of the living and non-living things in a particular area: biodiversity
The total variety of organisms that live in the biosphere: species
A group of organisms that breed and produce offspring that can breed:
All of the living things in a particular area:

multiplying and dividing the two decimals and the eqations by the same number of the overalls

sorry to break it to ya but no one can answer your question it's just

jk but i am serious about the part that most people cant answer it beacuse you did not mention the section you are talking about. but it would if you added some detail and were a bit more specific.

the atomic number of magnesium is 12. its nucleus must contain 12 protons and no electrons. the atomic number of an atom is determined by the number of protons.

magnesium is an electrolyte injection commonly used to treat low magnesium levels in your blood. it is also used to prevent or control seizures in women with preeclampsia or eclampsia.