An oxygen molecule consists of two oxygen atoms double-bonded together. It's nonpolar because the electrons are shared equally between both atoms.
Topic 2.1: 2.1 Types of Chemical Bonds
Oxygen Molecule (O2) cheat sheet for homework
Nonpolar Molecule: A molecule where electron distribution is equal and there are no partial charges on any part of it.
A chemical bond where four bonding electrons are shared between two atoms.
Elemental Molecules: Molecules composed entirely from atoms from the same element.