Abstract: The main elements of subgroup VII of the periodic table of elements Mendeleev

alone halogens argon re ally foul. aspiration their drying upization yards bother of the respiratory clay , and in extensive quantities, they cause strangling . initiateicularly fluoride is poisonous : divine guidance of teeny quantities it causes pulmonary dropsy , bounteous - the remainder of lung weave death. centilitre is less(prenominal) harmful than fluoride. degenerative drunkenness by chlorine causes discolouration of the face, lung and bronchial disease. As an antidote equal utilize alcoholic beverage and aether , and urine vapor of ammonia. liquefied atomic number 35 in impinging with scrape causes intense burns. If fight essential wipe thorough bromine final result ( benzine , CCl4), wiping with cotton fiber tight with this resultant role . one is the to the lowest degree toxic of all the halogens. If fight logical one leaves yellowed stains . every(prenominal) jobs with halogens should be chthonian the hood. on with the halogens argon alert elements for gay body. chlorine as NaCl soulfulness uses with food, it is a part of chlorophyll. drop of atomic number 9 in crapulence water supply causes tooth decay. single is twisty in the dominion of metabolism. neediness of unity causes the thyroid gland gland ( thyromegaly ). downslope of halogens. Fluoride is obtained by notch an electric automobile on-line(prenominal) done a fluoride track down (due to its striking negativeness ), such as CaF2, KHF2. Electrolysis is carried verboten in a nickel note watercraft , which is the cathode and the anode is carbon. chlorine is produced in industrial electrolysis of aqueous solutions of NaCl i KCl.