Definition. The normal concentration of sodium in the blood plasma is 136-145 mM. Hyponatremia occurs when sodium falls below 130 mM. Plasma sodium levels of 125 mM or less are dangerous and can result in seizures and coma. Description. Sodium is an atom, or ion, that carries a single positive charge.
reef1. 1  a ridge of rocks or sand, often of coral debris, at or near the surface of the water. 2  Mining. a lode or vein.
The Great Barrier Reef is the largest and best known coral reef ecosystem in the world. Its reefs, almost 3000 in total, represent about 10 per cent of all the coral reef areas in the world.he Government of Australia manages the reef through the Great Barrier Reef Marine Park Authority and in partnership with the Government of Queensland, to ensure that it is widely understood and used in a sustainable manner.