Properties of Compounds 1 Covalent distinct molecules held together by intermolecular forces relatively weak attractions, therefore low melting points not dense or hard poor heat and electricity conductors 2 Network Covalent exceptions continuous 3-D pattern?crystal Examples: diamonds, silicates 3 Network Covalent hard and brittle high melting points glassy luster 4 Ionic strong bonds, therefore high melting and boiling points hard solids can be split water-soluble good e? conductor in H2O, not as a solid 5 Ionic substances have low melting points. Ionic substances have low boiling points. Ionic substances don?t dissolve in water. Ionic substances are brittle. Question Because ionic bonds are strong, 6 Metallic carry electrons have luster (shine) malleable ductile 7 8