Final answer:
Silver forms a +1 ion by losing the single electron from its outermost 5s orbital, resulting in a stable-filled 4d subshell that b) resembles a noble gas configuration.
Step-by-step explanation:
The question pertains to why silver forms a +1 ion given its SPDF notation or electron configuration. Well, the electron configuration for a neutral silver atom is [Kr]4d105s1. When silver forms a cation, it loses the single electron from its outermost 5s orbital. This results in a configuration of [Kr]4d10, which resembles the electron configuration of a noble gas, with a filled d subshell taking the role of the outermost shell with a stable electron count contributing to the stability of the +1 ion. The removal of an s electron is due to the fact that electrons in the s orbital are generally easier to remove than the d or f electrons, particularly for transition metals, to which silver belongs. In choosing among the options provided, none directly describe this process accurately for silver; however, the principle of forming a pseudo-noble-gas electron configuration after losing an electron applies, similar to other transition metals and main group elements.