Why are some covalent compounds gas liquid or solid but all ionic compounds are solid?

Answer 1

In Ionic compounds, there is strong electrostatic forces of attraction between the Positve Cation and Negative Anion. A lot of energy is required to break this force hence it has a very high melting point/boiling point, this leads to most of ionic compounds being solid.

In covalent compounds, weak Van der Waals forces exists between discrete molecules (due to dipole attraction). These weak forces require little energy to break hence it has very low meling point/boiling point, this leads to most of the covalent compounds being volatile and hence more of liquid and gases form

Answer 2

This is because the intermolecular forces between molecules within a covalent compound are weak, so there isn't strong force attracted the bonds to each other. As a result, covalent bonds are weak and have low boiling and melting points unless the number of molecules is great (molar mass matters). In contrast, ionic compounds only have intramolecular forces within bonds, so their bonds are much stronger and hard to be separated. Thus, it takes more energy to break ionic bonds.

Answer 3

Ionic compounds generally have high melting points due to the strength of the bond in the ionic lattice. Covalent compounds are generally molecular and the forces holding the molecules together are weaker than ionic bonds and so their melting points are much lower. However large covalent molecules cane be solids ate room temperature, for example sulfur, S8 and phosphorus, P4, and the giant covalent stuctures

such as silica and diamond are extremely high melting.