Which of the following best describes what is unique about the electron configurations of transition metals?

• A. They have completely filled p orbitals in their ground state.
• B. Their electron configurations never deviate from the predicted order of filling.
• C. They often have partially filled d orbitals, even after losing electrons to form ions.
• D. Their valence electrons are always found only in s orbitals.

Answer: (C)

Verified step by step guidance

1. Understand that transition metals are elements found in the d-block of the periodic table, which means their valence electrons include electrons in the d orbitals.
2. Recall that the electron configuration of transition metals typically involves filling the (n-1)d orbitals along with the ns orbitals, where n is the principal quantum number of the outermost shell.
3. Recognize that what makes transition metals unique is that even after they lose electrons to form ions, they often retain partially filled d orbitals, which is different from main group elements where valence electrons are usually lost from the outermost s orbital first.
4. Note that the statement about completely filled p orbitals is incorrect because transition metals do not have their valence electrons in p orbitals; p orbitals are filled in main group elements.
5. Understand that the electron configurations of transition metals can sometimes deviate from the predicted order due to electron-electron interactions and stability considerations, so the claim that they never deviate is false.