Definition of beta. 1  1 : the 2nd letter of the Greek alphabet â see alphabet table. 2  2 : beta particle. 3  3 : a measure of the risk potential of a stock or an investment portfolio expressed as a ratio of the stock's or portfolio's volatility to the volatility of the market as a whole.
Chlorine has been used as a chemical warfare agent. Sources: In nature, chlorine is only found in the combined state, most commonly with sodium as NaCl and in carnallite (KMgCl 3 â¢6H 2 O) and sylvite (KCl). The element is obtained from chlorides by electrolysis or via the action of oxidizing agents. Element Classification: Halogen. Density (g/cc): 1.56 (@ -33.6 Â°C).
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.