something to look forward to... Year after year, Burpee's perennial seeds and plants will fill your home garden beds and borders. Select from our full palette of colors, textures, forms and fragrances to create the perennial garden of your dreams-a sensory pleasure for years to come.omething to look forward to... Year after year, Burpee's perennial seeds and plants will fill your home garden beds and borders. Select from our full palette of colors, textures, forms and fragrances to create the perennial garden of your dreams-a sensory pleasure for years to come.
A fullerene is a molecule of carbon in the form of a hollow sphere, ellipsoid, tube, and many other shapes. Spherical fullerenes are also called buckyballs, and they resemble the balls used in football (soccer). Cylindrical ones are called carbon nanotubes or buckytubes.he smallest fullerene is the dodecahedral C 20. There are no fullerenes with 22 vertices. The number of fullerenes C 2n grows with increasing n = 12, 13, 14, ..., roughly in proportion to n 9 (sequence A007894 in OEIS). For instance, there are 1812 non-isomorphic fullerenes C 60.
The configuration of six carbon atoms in aromatic compounds is known as a benzene ring, after the simplest possible such hydrocarbon, benzene. Aromatic hydrocarbons can be monocyclic (MAH) or polycyclic (PAH).Some non-benzene-based compounds called heteroarenes, which follow Hueckel'hÃ¼ckel s (rule for monocyclic: rings when the number of its-Ï electrons equals+4n, 2 where=n,0,1,2.......), 3 are also called aromatic. compoundshe term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered; the term was coined as such simply because many of the compounds have a sweet or pleasant odour.