3 and 4 are correct. A compound is a collection of two or more molecules, whereas a molecule is a collection of two or more atoms. 1 is not true because its talking about two atoms together which is a molecule. 2 is not true because it is still talking about two atoms which is still a molecule. 3 is true because molecule are subunits of compounds. 4 is true because elements and atoms are the same thing, and two or more atoms is a molecule.
ANSWER.
Explanation:
when one of the links in the food chain is no longer present the food chain breaks.sometime this can cause other animals in the food chain to disapper as well and the whole ecosystem can beome in balance or even colapse
I think the answer is either b or c
So it will float on top of the water
