Final answer:
To identify elements with partially filled d subshells, examine their position in the periodic table, particularly in the transition metals section, and the colors of the complex ions they form. The electron configuration of these elements typically shows a d subshell that is not completely filled (having fewer than 10 electrons).
Step-by-step explanation:
Identifying Elements with Partially Filled d Subshells
To determine if an element has a partially filled d subshell, look at its position on the periodic table. The periodic table is structured in such a way that the filling order of electron subshells is reflected. Generally, after filling the 4s subshell, electrons start to occupy the 3d subshell. This occurs as we move from left to right across the transition metals section, which includes elements from Scandium (Sc) to Zinc (Zn). The key is that transition metals typically have partially filled d subshells. You can also tell by the behavior of compounds these elements form. For example, metal ions with partially filled d subshells often form colored complex ions, unlike ions with either completely filled or empty d subshells, which tend to form colorless complexes.
Another clue is when an ion's electron configuration is notated. If the notated configuration ends with a d followed by a number less than 10 (indicating the number of electrons in that subshell), such as d³, it represents a partially filled d subshell. Thus, the order of subshell filling and the properties of elements and their ions can guide you in identifying whether an element has a partially filled d subshell.