Answer:
Each oxygen atom is connected to the central O atom with 2 covalent bonds.
Explanation:
Oxygen atoms are connected by two covalent bonds in the oxygen molecule from the Lewis structure, we see that the bond order for O2 is 2 (a double bond) this is clearly seen in the image attached. There are no resonance structures for the oxygen molecule since there are no partial bonds in the molecule, only the two covalent bonds present.
This structure of oxygen shown in the image is its only structure, showing the covalent bonds formed and other non bonding electrons present in the molecule. The octet rule is followed in drawing the structure. Each oxygen atom possesses an octet of electrons on its outermost shell.
Another explanation
A Lewis structure is also called a dot electron structure. A Lewis structure represents all the valence electrons on atoms in a molecule as dots. Lewis structures can be used to represent molecules in which the central atom obeys the octet rule as well as molecules whose central atom does not obey the octet rule.
Sometimes, one Lewis structure does not suffice in explaining the observed properties of a given chemical specie. In this case, we evoke the idea that the actual structure of the chemical specie lies somewhere between a limited number of bonding extremes called resonance or canonical structures.
The canonical structure of the carbonate ion as well as the lewis structure of phosphine is shown in the image attached to this answer.
Step-by-step explanation: