Final answer:
Sodium chloride (NaCl) and iron have high melting and boiling points as well as resistance to being crushed due to their ionic and metallic bonds respectively, making them hard to deform.
Step-by-step explanation:
Compounds that exhibit high melting and boiling points and are difficult to crush or deform typically have strong intermolecular forces. Among the options given, sodium chloride (NaCl) and iron are both known for their high melting and boiling points, as well as their resistance to being crushed. Sodium chloride is an ionic compound with ions held together in a crystalline lattice, characterized by high melting (801 °C) and boiling points (1413 °C). Iron, on the other hand, is a metallic solid with a melting point of 1538 °C. It is held together by metallic bonds that give it its solidity and high melting point. Meanwhile, carbon dioxide (CO2) and water (H2O) are molecular compounds with significantly lower melting and boiling points and are not as hard as ionic or metallic solids.