| environ. | transition element One of a group of metallic elements in which the members have the filling of the outermost shell to 8 electrons interrupted to bring the penultimate shell from 8 to 18 or 32 electrons; includes elements 21 through 29 (scandium through copper), 39 through 47 (yttrium through silver), 57 through 79 (lanthanum through gold), and all known elements from 89 (actinium) on | 过渡元素 (一类金属元素，这些元素最外层的8个电子未填满，导致倒数第二层有8到18或32个电子。这此元素包括21至29号元素(钪至铜)，39至47号元素(钇至银)，57至79号元素(镧至金)，以及89号以后的所有已知的元素。) |