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
This includes production of silver, iron, copper and other base metals from their ores. Smelting makes use of heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving just the metal base behind. The reducing agent is commonly a source of carbon such as coke, or in earlier times charcoal.