So Fe+2 is iron(II) and Fe+3 is iron(III). Many metals are of this type. Citric Acid Ionic or Covalent. Figure\(\PageIndex{6}\): Slide showing periodic trends for nomenclature of oxyanions of halogens. Citric acid ionic or covalent. Barium is an alkaline earth and always corms a cation of charge of [+2], while chlorine is a halogen and always form the chloride ion of [-1]. 1(x) + 1(-2) = 0. If it is a simple molecule we use Greek prefixes to identify the number of atoms of each type of element in the molecule. [CDATA[*/{"annotations":null,"assetRoot":null,"branding":null,"clientUrl":"https://cdn.hypothes.is/hypothesis/1.38.0/build/boot.js","oauthEnabled":null,"onLayoutChange":null,"openLoginForm":null,"openSidebar":null,"query":null,"services":null,"showHighlights":"always","sidebarAppUrl":"https://hypothes.is/app.html","subFrameIdentifier":"0250401132841779","pluginClasses":{}}/*]]>*/, /**/. [CDATA[*/{"annotations":null,"assetRoot":null,"branding":null,"clientUrl":"https://cdn.hypothes.is/hypothesis/1.38.0/build/boot.js","oauthEnabled":null,"onLayoutChange":null,"openLoginForm":null,"openSidebar":null,"query":null,"services":null,"showHighlights":"always","sidebarAppUrl":"https://hypothes.is/app.html","subFrameIdentifier":"05514394087373824","pluginClasses":{}}/*]]>*/, /**/, /**/, /*