Back to Top. 1  These are the waves which are having the lowest frequency in the electromagnetic spectrum. They are given out by transmitter. 2  They are formed as a result of thunder, lightning etc. 3  They are used in communication mostly.  They are of four types of radio waves 1  namely: Long wave.  Medium 1  wave. Ultra high frequency  (UHF)
What is the role of arsenic in the mining industry . Arsenic is a naturally occurring element commonly found as an impurity in metal ores, and is produced commercially for use in pesticides, wood preservatives, and , Get Price arsenic - definition of arsenic by Medical dictionary
It is also released into the environment by volcanoes and mining processes. Arsenic in groundwater is a widespread problem. Arsenic levels tend to be higher in drinking water that comes from ground sources, such as wells, than from water from surface sources, such as lakes or reservoirs.