Answer:
D. Carbon and oxygen form covalent bonds but sodium and chlorine form ionic bonds
Step-by-step explanation:
Chemical bonds form between the atoms of elements. The types of chemical bondings that form are: covalent bond, ionic bond and more. Covalent bonds are bonds formed when atoms share valence electrons rather than transfer it. The shared bonding is in such a way that the outermost shell of both atoms are filled. This is the case of carbon and oxygen atoms in the diagram.
On the other hand, ionic bonding involves the transfer of electrons from one atom to another in order to form electrically charged ions that are bound to one another. This is the case of sodium atom, which has one valence electron in its outermost shell and transfers it to chlorine atom, which has seven electrons in its outermost shell. The sodium atom becomes a positively charged ion (+1) while the chlorine atom becomes negatively charged (-1).