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).
Nearly all chlorine in the Earth's crust occurs as chloride in various ionic compounds, including table salt. It is the second most abundant halogen and 21st most abundant chemical element in Earth's crust.6 Cl is produced in the atmosphere by spallation of 36 Ar by interactions with cosmic ray protons. In the subsurface environment, 36 Cl is generated primarily as a result of neutron capture by 35 Cl or muon capture by 40 Ca. 36 Cl decays to 36 S and to 36 Ar, with a combined half-life of 308,000 years.