Ionic structures are solids at rooms temperature, because of the amount of electrostatic forces that are in play. It is hard to overcome the strong electrostatic forces, therefore they have high melting and boiling points. Liquids of the metals carry energy too because when the ionic compounds have melted, the ions move and carry electric charge. They too also conduct electricity when in another solution.
Unlike with metals, non-metals have low melting and boiling points, because the bonds only act between the atoms themselves and therefore simple molecules have little attraction to each other - these are known as intermolecular forces. Those of the smallest atoms, like Hydrogen and Chlorine, are gases at room temperature. Larger molecules contain larger atoms and therefore Bromine and Hydrogen Chloride are liquid at room temperature. The largest molecules are solids at room temperature like Iodine.
Giant covalent structures are when the covalent bonds are strong and there are many of them. Therefore, it takes a lot of energy to break the lattice.
Diamond is a form of carbon where carbon is covalently bonded to 4 other carbon atoms. Therefore, diamond is hard.
Graphite is also a form of carbon where carbon is covalently bonded to 3 other carbon…