G ggordil Guest Jan 9, 2009 #2 "an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell" from wikipedia This means the elements in the middle of the periodic table.
"an element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell" from wikipedia This means the elements in the middle of the periodic table.
