Pulmonary arterial hypertension is a rare but severe disease with an estimated five-year survival rate of only 57% after diagnosis, according to the Registry to Evaluate Early And Long-term PAH disease management (REVEAL), which registers data from patients in the United States.
Concentration of elements in the ocean relative to the total concentration in the bulk silicate Earth (BSE). Of all the elements, only Cl and Br have a significant fraction in the ocean (see inset), indicating the extreme hydrophilic character for the heavier halogens.
It is the second most common halogen on Earth. The element itself is the 21st most common element, at about 170 parts per million. It took almost 200 years from the discovery of chlorine gas for it to become recognized as an element.Sodium chloride is the most common compound of chlorine, and it is abundant on Earth, especially in seawater.Chlorine in its pure form is yellowish-green, but its common compounds are typically colorless.t took almost 200 years from the discovery of chlorine gas for it to become recognized as an element. Sodium chloride is the most common compound of chlorine, and it is abundant on Earth, especially in seawater.