Concept:A double covalent bond involves sharing two pairs of electrons between two atoms.
Single covalent bonds share only one pair of electrons.
Explanation:Oxygen exists as
O2, with the structure
O=O, so it contains a double bond.
Carbon(IV)oxide is
CO2, with the structure
O=C=O, so it contains double bonds.
Ethene is
C2H4, which has the structure
H2C=CH2, so it contains a double bond between the two carbon atoms.
Water is
H2O, with the structure
H−O−H, containing only single covalent bonds between hydrogen and oxygen.
Therefore, water is the molecule that does not have a double covalent bond between its atoms.
Answer:D. water