Many scientific and technological advances can be credited to nanoscience and nanotechnology. Nanostructures are structures that range between 1 nm (molecular scale) and 100 nm in at least one dimension. Most are synthetic and can be engineered to wide range of physical properties. Nanoribbons, nanotubes, nanorings, quantum dots and nanoparticles are common nanostructures. At the nanometer length scale, materials and structures behave differently, which offers exciting opportunities for scientific discoveries and technological advances. We use the tools of physics to understand new materials and atomic-size structures that will enable future technological breakthroughs.