<prompt> All are trace elements except -IronFluoridePotassiumZinc  <response>: Trace elements are elements required by the body in quantities of less than a few milligrams per day.eg.iron,iodine,flourine,zinc,copper cobalt,chromium,manganese,molybdenum,selenium,nickel,tin,silicon and vanadium.Ref.PARKS textbbok of sociala and preventive medicine 21st edition page no.573 