Crystals are characterized by particular patterns that repeat in how many dimensions? A. three dimensions

B. one dimension only

C. two dimensions only

A. three dimensions

Explanation:

Crystal lattice have a three dimensional array of repeating units. For example, in the NaCl crystal the repeating units are the Na⁺ and Cl⁻ ions. The Na⁺ and Cl⁻ ions are arranged alternately along the x, y and z axis. The smallest repeating unit of a cell is called unit cell. Crystal lattice have a definite geometry which is because of this rigid array of unit cells.

A option is correct answer.