Question

What kind of solid often has the highest melting points?

Answer 1

Hint : A substance's melting point is the temperature at which it transitions from solid to liquid state. The liquid and solid states are in equilibrium at the melting point. A substance's melting point is determined by pressure and is normally defined at normal pressure, such as $1$ atmosphere.

Complete Step By Step Answer:
Based on how the particles are arranged, solids are classified into $2$ categories: crystalline solids and amorphous solids. Ionic solids, molecular solids, covalent network solids, and metallic solids are the $4$ varieties of crystalline solids.
Ionic solids: Crystals of ionic compounds are made up of ions with opposing charges: a cation and an anion. Ionic bonds are difficult to break because of the intense attraction between opposite charges. Ionic compounds have very high melting points, ranging from $300 - {1000^ \circ }C$.
Molecular solids: Covalently bound molecules are drawn to each other by electrostatic forces in molecular solids. Most molecular solids melt at temperatures below ${300^ \circ }C$.
Covalent network solids: Individual molecules do not exist in a network solid. Massive crystals are formed when atoms are covalently bonded in a continuous network. The melting point of the diamond is over ${3500^ \circ }C$, while the melting point of $Si{O_2}$ is around ${1650^ \circ }C$. Covalent network solids are among the highest melting substances known.
Metallic solids: Metallic solids are metal atoms that are held together by metallic bonds.
They have high melting points, can range from smooth and malleable to extremely stiff, and are excellent electrical conductors.
Amorphous solids: Since the bonds do not dissolve all at once, an amorphous solid does not have a definitive melting point; instead, it melts slowly over a variety of temperatures.
Therefore, we can conclude that among all the various types of solids, a covalent network solid often has the highest melting points.

Note :
Amorphous ice is a dense form of water that is amorphous in nature. Despite the fact that nearly all water ice on Earth is crystalline. In the interstellar medium, amorphous ice predominates, making this the most natural configuration for ${H_2}O$ in the universe at large.