Which of the following best describes bulk materials in terms of size?

Bulk materials are defined as materials that are larger than 100 nanometers in size, which is the reason why this choice is considered correct. In the context of nanotechnology, the size of materials is crucial, as different scales have distinct physical and chemical properties. Bulk materials, typically measured in micrometers or larger, display bulk properties that are different from those of nanomaterials, which range from around 1 to 100 nanometers.

Understanding this distinction is important in nanotechnology, where manipulation at the nanoscale can yield enhanced properties such as increased strength, lighter weight, or improved chemical reactivity compared to their bulk counterparts. This highlights the significance of size in determining the behavior of materials and their applications in various fields including electronics, medicine, and materials science.