Question

QUESTION 2 Amorphous solids have a well defined crystal lattice. True False QUESTION 3 Consider these two classes of solids: covalent-network solids and molecular solids. Which answer below best explains why these two types of solids differ so greatly in terms of their relative hardness and melting points? O A. The atoms in covalent-network solids are more polarizable than those in molecular solids. B. The molecules in molecular solids have stronger covalent bonding than covalent-network solids do. OC. The molecules in molecular solids are held together by weak intermolecular interactions. OD. All these divisions over classes of solids and the properties they possess -- why can't we just get along together?!? E. Molecular solids are denser than covalent-network solids.

Answer 1

2. Amorphous solids have irregular crystal structures. You can find many different shapes of crystals in an amorphous solid. That's why they have low boiling and meltjng points.

So the given statement is false.

3. The most correct answer is c. In a covalent network, atoms or molecules are bonded by covalent bonds in a network fashion. So, the whole network becomes one big molecule. That's why they are very hard. On the other hand, in a molecular solid, molecules interact with each other by weak intermolecular forves which are much much weaker than the covalent bonding. So, molecular solids have low hardness.

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