In which block of the periodic table do elements with partially filled d orbitals reside, and where are the noble gases located?

• A. d-block; noble gases are in the s-block
• B. p-block; noble gases are in the p-block
• C. d-block; noble gases are located in the p-block
• D. f-block; noble gases are in the p-block

Answer: (C)

This question tests how blocks on the periodic table map to the subshell being filled by valence electrons. Elements with partially filled d orbitals are in the d-block because their outer electrons occupy the d subshell, which is the hallmark of transition metals. Noble gases have a complete outer p subshell, so they sit in the p-block. Therefore, the described pairing is that the d-block contains elements with partially filled d orbitals, and the noble gases are located in the p-block. (Note that helium is sometimes shown with the s-block in some diagrams, but the general placement for noble gases is the p-block.)