Which has covalent bonds? a) glucose b) table salt c) steel alloy d) iron oxide - rust

- A) glucose has covalent bonds.

Explanations:- Glucose is a molecule that has carbons, oxygen and hydrogen. All these are non metals and do sharing of electrons to gain their nearest noble gas configurations and so glucose has covalent bonds.

Table salt is NaCl. Na is a metal and Cl is a non metal so the bond formed between them is ionic.

Steel alloy has Iron and carbon and so it would have ionic and metallic bonding.

Iron oxide also has a Iron(metal) and oxygen(non metal) and so it has ionic bond.

So, the only and only correct choice is A) Glucose.