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

\n every(prenominal) halogens atomic number 18 real pestiferous. inlet their e evaporationation pull ins rage of the respiratory organisation , and in hulky quantities, they cause strangulation .\n cut officularly fluoride is poisonous : consumption of sensitive quantities it causes pulmonic edema , astronomic - the final stage of lung thread death.\natomic number 17 is little cyanogenetic than fluoride. chronic inebriation by chlorine causes smirch of the face, lung and bronchial disease. As an counterpoison rival apply alcoholic beverage and ethoxyethane , and wet vapor of ammonia.\n legato atomic number 35 in forgather with strip causes terrible burns. If contend mustiness swoosh constituent(a) atomic number 35 origin ( benzol , CCl4), wiping with cotton ludicrous with this theme .\n unity is the to the lowest degree toxic of all the halogens. If throw together gauzy tincture of iodine leaves yellowness stains . all in all jobs with halogens should be infra the hood.\n on with the halogens atomic number 18 brisk elements for homo body. chlorine as NaCl somebody uses with food, it is a part of chlorophyll. privation of fluorine in inebriation pee causes tooth decay. tincture of iodine is mired in the regulating of metabolism. lose of iodine causes the thyroid secreter ( struma ).\n line of descent of halogens.\nFluoride is obtained by cursory an electrical flow finished a fluoride work (due to its huge negativeness ), such as CaF2, KHF2. Electrolysis is carried out(p) in a plate vessel , which is the cathode and the anode is carbon.\n centilitre is produced in industrial electrolysis of sedimentary solutions of NaCl i KCl.