Final answer:
The melting point is the temperature at which a solid changes into a liquid. It is dependent on the strength of attractive forces within the solid. Different substances have different melting points based on the type of bonds they form.
Step-by-step explanation:
The melting point is the temperature at which a solid changes into a liquid. As a solid is heated, its particles vibrate more rapidly as it absorbs kinetic energy. Eventually, the organization of the particles within the solid structure begins to break down, and the solid starts to melt. At its melting point, the disruptive vibrations of the particles of the solid overcome the attractive forces operating within the solid. The melting point of a solid is dependent on the strength of those attractive forces.
For example, sodium chloride (NaCl) is an ionic compound that consists of a multitude of strong ionic bonds. Sodium chloride melts at 801°C. On the other hand, ice (solid H₂O) is a molecular compound composed of molecules that are held together by hydrogen bonds. Though hydrogen bonds are the strongest of the intermolecular forces, the strength of hydrogen bonds is much less than that of ionic bonds. The melting point of ice is 0°C.