Bucky Ball Definition: Bucky ball is defined as the hollow spherical molecule composed of a large number of carbon atoms. Bucky Ball (Fullerene) Structure: Fullerenes are molecules composed entirely of carbon atoms. They resemble graphite but besides hexagonal carbon rings also have pentagonal carbon rings. Fullerenes are hollow spheres, ellipsoid, tubes (nanotube), etc. The sphericalBucky Ball (Fullerene)- Allotrope of Carbon