Final answer:
The true melting point of a substance is when it changes from solid to liquid, influenced by intermolecular forces. Water's melting point is at 0°C, while sodium chloride melts at 801°C, demonstrating how bond strength affects melting points.
Step-by-step explanation:
The true melting point of a substance is the temperature at which its solid form changes into a liquid. For example, the equilibrium of water melting and freezing occurs at 0°C, where H₂O as a solid and as a liquid can coexist. Substances like sodium chloride (NaCl), which have strong ionic bonds, have a higher melting point, such as 801°C, due to the strength of the attractive forces within their structure. Conversely, ice, composed of H₂O molecules held together by hydrogen bonds, has a melting point of 0°C because hydrogen bonds, while strong, are not as strong as ionic bonds.
All materials have a melting point that is influenced by intermolecular forces. The melting point of a substance is an important physical property and is determined by the kinetic energy of the particles and the strength of the bonds holding them together. Understanding the concept of melting points is crucial in fields such as materials science and engineering.