O2 molecule consists of two oxygen atoms. In the molecule, nuclear force between the nuclei of the two atoms:

1. is not important because nuclear forces are short-ranged

2. is as important as electrostatic force for binding the two atoms

3. cancels the repulsive electrostatic force between the nuclei

4. is not important because oxygen nucleus have equal number of neutrons and protons

(1) Hint: Nuclear forces are short-ranged forces.
In the molecules, nuclear force between the nuclei of the two atoms is not important because nuclear forces are short-ranged.