Which statement is true about a solid?

• A. Definite shape
• B. Indefinite shape
• C. Fluid behavior
• D. Compressibility

Answer: (A)

Solids have a definite shape because their particles are arranged in a fixed, tightly bound structure. The strong intermolecular or lattice forces lock the particles in place, so the solid maintains its own shape and volume and does not take the shape of its container. This is in contrast to liquids and gases, which have indefinite shape and will flow to fill a container. Solids do not exhibit fluid behavior under ordinary conditions; they resist flow and deformation until enough force is applied to break bonds or yield the material. Regarding compressibility, solids are only slightly compressible, which is why they’re often treated as incompressible in basic analyses; but the hallmark property that makes the correct choice definite shape is the fixed arrangement of particles.