How does the density of a liquid generally compare to the density of the same substance in its solid state?

• A. The solid usually has a higher density than the liquid.
• B. The liquid is always less dense than the gas form.
• C. The liquid usually has a higher density than the solid.
• D. The densities of the solid and liquid are always equal.

Answer: (A)

Verified step by step guidance

1. Recall that density is defined as mass per unit volume, given by the formula \(\rho = \frac{m}{V}\), where \(\rho\) is density, \(m\) is mass, and \(V\) is volume.
2. Understand that when a substance changes from liquid to solid, its particles typically become more closely packed, which usually decreases the volume while the mass remains constant.
3. Since density depends inversely on volume, a decrease in volume with constant mass results in an increase in density for the solid compared to the liquid.
4. Note the important exception of water, where the solid form (ice) is less dense than the liquid due to its unique molecular structure, but this is not the general case for most substances.
5. Conclude that generally, the solid state of a substance has a higher density than its liquid state because solids tend to have particles packed more tightly than liquids.