Silicon nitride 1Si3N42, a high-temperature ceramic useful for making engine components, is a covalent network solid in which each Si atom is bonded to four N atoms and each N atom is bonded to three Si atoms. Explain why silicon nitride is more brittle than a metal like copper.

Video transcript

Hello everyone today. We have the following problem. Silicon carbide is a ceramic used in electronic applications that operate at high temperatures and high voltages debate to silicon carbide has a zeke blend a structure similar to a diamond wherein each silicon atom is bonded tetra. He'd really to four carbon atoms and each carbon atom is also bonded tetra. He'd really to four silicon atoms, which of the following statements explains why silicon carbide is generally more brittle than a metal. So as stated before, This silicon atom is bonded tetrahedron to four carbon atoms. So an example of this would be this one silicon bonded tetra. He'd really or four times to four carbon atoms and at the same time each carbon atom is bonded to for silicon atoms. And so this is going to form a co violent network solid. So this is an example of a Covalin network solid in a metallic solid. So when we have a metallic solid, the valence electrons abbreviated as ve they are de localized. So they are de localized throughout the structure of the solid. And this is known as a sea of electrons similar to a sea of water. And so because they are de localized, they are very, they are prone to being malleable and because they are malleable, they can be deformed due to the atoms being able to slip past one another. On the other hand, with Covalin bonds due to the Covalin bonds present in this network solid. So due to the Covalin bonds, they prevent Adams from slipping past one another. So Covalin bonds prevent atoms from slipping past bundler and so therefore they cannot be deformed when stress is applied. Because of these strong Covalin network solid bonds with these answer choices in mind. Answer choice C. Best answers the question when stress is applied to silicon carbide, it cannot deform to adapt to stress because the strong Covalin bond prevents the atoms from slipping past one another. And with that we have answered the question overall. I hope that this helped, and until next time.