Very high melting<span> points - Substances with giant covalent structures have very high</span>melting<span> points, because a lot of strong covalent bonds must be broken. Graphite, for example, has a </span>melting point<span> of more than 3,600ºC. Variable conductivity - Diamond does not conduct electricity.</span>
A proton repelling another proton
Like charges of the protons would repel one another.
