Which of the following are likely to form a covalent bond?
silver atoms
argon atoms
sodium and chlorine atoms
carbon and chlorine atoms

Carbon and chlorine atoms, have a blessed day! :)

carbon and chlorine atoms

Explanation:

Chlorine and carbon atoms would form covalent bonds due to the electro negative difference between the two atoms. Silver atoms would form metallic bonds between silver atoms. Argon is an inert gas and most inert gases are held by weak dispersion forces. Sodium and chlorine atoms will form ionic bonds due to the large electro negative difference between the two atoms.

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.