Silver (Z = 47) has a completely filled 4d subshell (4d10) in its ground state. Why is it still regarded as a transition element?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → It can show the +2 oxidation state, in which its 4d orbitals are incompletely filled.
By the IUPAC definition, a transition metal has an incomplete d subshell either in the neutral atom or in its ions.
Silver atom is 4d10 5s1, but in the +2 state (Ag2+) it loses the 5s electron and one 4d electron, giving 4d9. This partly filled d subshell in an ion makes silver a transition element.
Why the other options are incorrect
Option (2) Its outermost 5s orbital contains only one electron. — Incorrect. This is true of the atom, but the definition is about the d subshell, not the s orbital. Copper and gold also have one s electron.
Option (3) It is placed in group 11, along with copper and gold. — Incorrect.
A place in the d-block is not enough: zinc, cadmium and mercury of group 12 are also in the d-block.
They are not regarded as transition metals because their d subshell is full in the atom and in their common ions.
Option (4) Its Ag+ ion has the 4d10 configuration. — Incorrect. A completely filled 4d10 ion argues against transition character; zinc is not a transition element for this very reason.
NCERT (2026-27 edition):
4.1 Position in the Periodic Table – “…Now according to IUPAC, transition metals are defined as metals which have incomplete d subshell either in neutral atom or in their ions.”
Answers to Some Intext Questions – “4.1 Silver (Z = 47) can exhibit +2 oxidation state wherein it will have incompletely filled d-orbitals (4d), hence a transition element.”