Describe giant covalent substances as structures where atoms are linked by many strong covalent bonds.

Giant covalent substances are characterized by a structure in which atoms are interconnected by numerous strong covalent bonds. This extensive network of bonds results in very high melting and boiling points, as a significant amount of energy is required to break these bonds. Examples of giant covalent structures include diamond and graphite, where the arrangement of atoms contributes to their distinct physical properties. The strength and number of these covalent bonds are crucial in defining the stability and hardness of giant covalent substances.