I believe D. because all the organisms that live in a lake can be a bunch of living things that would be considered a population and not a species. I canceled out B. from the get go because, I don’t believe non living organisms can be in a population ?
Please get back to me if I’m right or wrong :)
In the problem, we are tasked to solved for the amount of carbon (C) in the acetone having a molecular formula of C 3 H 6 O. We need to find first the molecular weight if Carbon (C), Hydrogen (H), Oxygen (O).
Molecular Weight:
C=12 g/mol
H=1 g/mol
O=16 g/mol
To calculate for the percent by mass of acetone, we assume 1 mol of acetone.
%C=
%C=62.07%
Therefore, the percent by mass of carbon in acetone is 62.07%
Https://us-static.z-dn.net/files/d49/33d4ec86853ef95e6f6c14242c663be4.png
all of the above is the answer :)