Which term refers to a particle that is between 1 and 100 nanometers in size?

The term that refers to a particle sized between 1 and 100 nanometers is "nanoparticle." Nanoparticles possess unique properties due to their small scale, such as increased surface area relative to volume, which can enhance their reactivity and influence their interactions with other materials. This size range is critical because it allows for applications in various fields, including medicine, electronics, and materials science, where the properties of materials can be significantly altered at the nanoscale.

Nanomaterials are a broader category encompassing various types of materials that have nanoscale components, of which nanoparticles are a specific type. Nanocomposites involve a combination of materials at the nanoscale to enhance material properties, while nanorobots refer to microscopic machines designed for specific tasks at the nanoscale. Thus, while the other terms relate to nanotechnology, they do not specifically define the size range of interest as nanoparticles do.