Bonding and physical properties

Melting and boiling points of Ionic solids and Metals

Ionic solids: energy is needed to overcome strong electrostatic attractions between oppositely charged ions

Metals: energy is needed to overcome metallic bonding

Melting and boiling points of Gaint Covalent Structures and Simple Molecular Substances:

Giant Covalent Structures: many strong covalent bonds must be broken

Simple Molecular Substances: energy is needed to overcome intermolecular forces, not the covalent bonds inside molecules

Electrical Conductivity in Metals and ionic compounds:

Metals conduct because delocalised electrons are mobile

Ionic compounds conduct when molten or dissolved in water if ions are mobile; solid ionic compounds do not conduct because ionsare in fixed positions.

Electrical Conductivity in Graphite, Diamond and Simple molecular substances:

Graphite conducts because it has delocalised electrons

Diamond does not conduct because all four outer electrons of each carbon atom are used in covalent bonds

Most simple molecular substances do not conduct because they lack mobile charged particles