Final answer:
According to the IUPAC definition, a transition element must have partially filled d orbitals to be considered a transition metal. Silver does not meet this criterion strictly as it has fully filled d orbitals, but it is still commonly referred to as a transition metal being part of the d-block elements. Therefore, the answer is C - It has a completely filled d orbital.
Step-by-step explanation:
The question at hand asks whether a silver atom can be considered a transition element given that it has completely filled d orbitals in its ground state. Transition metals are defined by the International Union of Pure and Applied Chemistry (IUPAC) as elements that have, or can form, one or more stable ions with partially filled d orbitals. This definition excludes elements with fully filled or empty d orbitals from being classified as transition metals when forming ions.
Silver, with its electron configuration [Kr]4dⁱ⁰5s¹, actually has a full 4d level in the metal. However, upon ionization to form Ag⁺⁴, it loses the 5s electron, leaving the 4d level full. This would indeed be at odds with the strict definition of a transition element as it does not have partially filled d orbitals in the commonly occurring silver ion (Ag⁺⁴). Nonetheless, silver is typically still considered as part of the transition metals category in the broader sense because the term is frequently used to refer to the entire d-block, which includes silver. Therefore, option C is the correct one as it acknowledges that silver has a completely filled d orbital and yet is still identified as a transition element in a more general context.
It is important to clarify that the strictly correct answer according to the IUPAC definition would be different if the question asked about transition metal ions specifically, rather than transition elements in general.