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
Many water sources in the world have high levels of arsenic in them, both due to normal arsenic leaching out of the ground and from mining and industrial waste. Recent examples of concerns about arsenic have surfaced because of its presence in apple juice.