Question

What is the charge of ${O_2}$?

Answer 1

The molecules are formed by the combination of atoms, atoms are tiny particles. These atoms have electrons in their shells and try to attain the nearest noble gas configuration. Then the atom turns into ions having charge. Molecules will also carry, but non polar molecules will not carry any charge.

Complete answer:
Given a molecule is oxygen gas, it is a diatomic molecule. The oxygen gas consists of two oxygen atoms. The two oxygen atoms are bonded to each other through covalent sigma bonds. Each oxygen atom has $8$ electrons in its outermost shell. The valence electrons in each oxygen atom are $6$. Out of these $6$ electrons two electrons from each oxygen atom are involved in bond formation. Thus, two electrons were consumed for the bond formation, remaining four electrons will exist as lone pairs on oxygen atoms.
Thus, the two oxygen atoms have equal electrons and there is no electronegativity difference, which leads to non-attraction between two atoms. It results in no net movement of electron flow from one atom to another atom. Thus, it is a nonpolar molecule.
The non-polar molecules do not have any charge, Thus, the charge on oxygen gas is Zero.

Note:
Many gases like oxygen gas, nitrogen gas, hydrogen gas exist as a diatomic molecule. These all-diatomic molecules are non-polar. Thus, these gases do not carry any charge. But oxygen gas can form oxides like peroxides and superoxides carrying charges, but oxygen gas will not carry any charge.