[thusspokeL]

Hello everyone,
I was recently learning about covalent and network covalent bonds when I figured I couldn't distinguish between covalent and network covalent bonds in terms of chemical formulas. For example, SiC or silicon carbide is network covalent, but I have no idea how to figure out why it is network covalent.

Thanks in advance

[thetada]

I'm not familiar with those terms but it sounds like what I would describe as simple vs giant covalent. Giant covalent structures, like diamond, form huge lattices of repeating units, in a similar way to metals and ionic compounds. This means that from one edge of a diamond to the other, all the carbon atoms are held together by strong covalent bonds. Simple covalent refers to molecules such as water and methane, the molecules of which contain just 3 and 5 atoms respectively. This smaller number of atoms is also held together by strong covalent bonds, but the attraction between the molecules is much weaker, explaining why simple covalent substances tend to have very low melting points, whereas giant covalent substances have very high melting points. See the link for further info.... http://www.chemguide.co.uk/atoms/structures/giantcov.html