Which term describes a solid matter with atoms arranged in a regular, repeating pattern?

• A. Amorphous substance
• B. Crystal
• C. Lattice
• D. Pattern

Answer: (B)

A crystal is a solid whose atoms are arranged in a regular, repeating pattern. That long-range order extends in three dimensions, giving the material a definite shape and high symmetry. This orderly arrangement is what sets crystalline solids apart from others.

The word lattice refers to the abstract grid that describes the positions of atoms in that repeating pattern; it’s the framework behind the order, not the material itself. An amorphous substance lacks this long-range repetition, with atoms arranged irregularly, so there isn’t a true repeating pattern. Pattern is too general to capture the specific, periodic arrangement that characterizes crystals. So the solid described here is best called a crystal.