What does the chemical formula show? a) The number of elements in each molecule
b) The number of atoms in each molecule
c) How heavy the molecule is.
d) The elements in the molecule and the number of atoms of each one .

A

Explanation:

You can eliminate C because you need to consult a periodic table to determine the mass (not the weight).

There are other answers you could use. The wording is awfully sloppy.  D is an example of that. The elements part is true, the atoms part is not really true in all cases.  For example NaCl is table salt and both the elements are ions, not atoms. Na is plus ion and Cl is minus one. B is wrong for the same reason.

I think in the end I would choose A.  I think this is a very sly question. It is not really testing chemistry. It is testing how well you know your definitions.