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).
Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele, who called it dephlogisticated marine acid (see phlogiston theory) and mistakenly thought it contained oxygen. Davy showed that the acid of Scheele's substance, called at the time oxymuriatic acid, contained no oxygen.