Answer:
C) There are two atoms in the molecule.
Explanation:
In convention (accepted style) of writing out chemical equations and formular, it is understood that the subscript after an element tells us the number of atoms of said element.
For example, in the compound below, we can tell that;
H₂CO₃
There are 2 hydrogen atoms, 1 carbon atom and 3 Oxygen atoms.
We apply same principle to O2 and we now know the number 2 signifies the number of atoms present in the molecule.
Applying elimination on the other options, we have;
A) This option is not correct because electrons transferred or gained are represented by a charge which is the superscript after the element. E.g O²⁻
B) This option is wrong because sharing of electrons are not represented in the formular of a molecule or compound.
D) Valance electrons are usually represented by oxidation number. So this is wrong too.