Ankylosing spondylitis. Ankylosing spondylitis (AS) is a type of arthritis in which there is long term inflammation of the joints of the spine. Typically the joints where the spine joins the pelvis are also affected. Occasionally other joints such as the shoulders or hips are involved. Eye and bowel problems may also occur.
The allotropes of carbon. Three forms (or 'allotropes') of pure carbon are diamond, graphite and buckminster fullerene (or 'buckyballs'). In all three allotropes the carbon atoms are joined by strong covalent bonds but in such different arrangements that the properties of the allotropes are very different.he allotropes of carbon. Three forms (or 'allotropes') of pure carbon are diamond, graphite and buckminster fullerene (or 'buckyballs'). In all three allotropes the carbon atoms are joined by strong covalent bonds but in such different arrangements that the properties of the allotropes are very different.
Examples of elements that have allotropes include carbon, oxygen, phosphorus, and sulfur. Allotropes. Oxygen is a chemical element represented by the symbol 'O' and has the atomic number 8. It is the first element in Group VI A of the modern periodic table.ioxygen. Dioxygen (O 2) is the most common form of elemental oxygen. It is a colorless gas at room temperature and forms about 21% of the earth's atmosphere. It exists as a diradical, and is the only allotrope that has unpaired electrons.