This element is one of the transition elements that doesn’t place the additional electrons in the outer shell, but in the one underneath. For the fourth period/row, all of these electrons build the third shell to a maximum of 18 electrons. Remember that the first eight were placed during our trip through the third period/row. The fourth row of the periodic table has transition metals ranging from scandium (21) to zinc (30).

Another transition element and another metal. While you may think of iron as a magnetic metal, not all forms of iron are magnetic. Scientists have found four allotropic forms of iron. Iron continues the pattern of earlier transition elements and adds an electron to the third shell and produces and electron configuration of 2-8-13-2.