Final answer:
Sheet silicates exhibit a single strong cleavage in one direction due to their two-dimensional structure of linked silica tetrahedra.
Step-by-step explanation:
The group of silicate minerals that exhibits a single strong cleavage in one direction is the sheet silicates. These minerals are structured in such a way that their silica tetrahedra are linked together in flat two-dimensional sheets. This configuration results in a mineral that breaks along these sheets, showing a single, strong cleavage direction. Examples of sheet silicates include minerals like muscovite and biotite. This allows the mineral to easily break along the planes of these sheets, resulting in a single strong cleavage direction.