Answer:
The correct answer is d) Crystalline solids.
Crystalline solids are a type of solid structure that has a definite and sharp melting point. Unlike amorphous solids, which do not have a well-defined melting point, crystalline solids have a highly ordered arrangement of particles. This regular arrangement allows for a specific temperature at which the particles begin to break apart and transition from a solid to a liquid state.
For example, consider the melting point of table salt (sodium chloride), which is a crystalline solid. At temperatures below its melting point of 801 degrees Celsius (1474 degrees Fahrenheit), table salt exists as a solid with a rigid and fixed structure. However, once the temperature reaches 801 degrees Celsius, the particles of table salt begin to vibrate more rapidly, causing the solid structure to break down, and the substance becomes a liquid.
In contrast, amorphous solids, such as glass, do not have a specific melting point. They soften gradually over a range of temperatures without a distinct transition from solid to liquid state. This is because amorphous solids lack the long-range order found in crystalline solids, making their melting behavior less defined.
Therefore, the solid structure that has a definite and sharp melting point is d) Crystalline solids.
Step-by-step explanation:
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