O2 is not a molecule. It’s two atoms bonded, meaning they are sharing electrons to make both stable enough for life.
Oxygen is made up of two atomic symbols, one with an “O” and the other symbolized with a “+”. Underneath the + symbol is a dotted box filled with four dots (representing the second element). One half of this box lies on top of the word “atom,” while the other half remains below it and acts as its base. In small print on each side is written hydrogen-1 isotope, which stands for that element in its strongest form since it contains only one neutron in its nucleus (in most cases).