Which type (or types) of crystalline solid is characterized by each of the following? (c) high melting point and poor electrical conductivity;

Video transcript

Hey everyone, we're asked to identify the type or types of crystalline solid that possess the following properties. Poor thermal conductor, hard and brittle. First, we have an ionic solid, as we've learned, an ionic solid is held by strong electrostatic attractions. And these are also poor conductors of heat and electricity. And these also have very high melting points. So it looks like A is one of our answers. Let's go ahead and assess B. For B. We have a molecular solid. Molecular solids are held by inter molecular forces and these are typically soft and they are poor conductors of heat and electricity. And these also have relatively low melting points, depending on the type of inter molecular force. Now be cannot be our answer. Since we're looking for a crystalline solid that is hard and molecular solids are soft. Now let's go ahead and look at C. For C. We have metallic solids. Metallic solids are composed of metal with another metal or by itself, and it's held by metallic bonds. Now, these are good conductors of heat and electricity, and these are lustrous, malleable and ductile, and they have relatively low melting points. But since we're looking for a poor thermal conductor, C cannot be your answer. Next. We have a Covalin network solid and these are where atoms are bonded by covalin bonds in a single continuous network. Now, these are also poor conductors of heat and electricity and they also have very high melting points. So it looks like d is also going to be one of our answers. So our final answer here is going to be answer choice F. That states that A and D fit our description. Now, I hope that made sense and let us know if you have any questions.