Silver is a transition element and has a partially filled 4d- orbital having 9 electrons and a 5s orbital having 2 electrons in it. In order to achieve stability, silver must have completely filled d-orbital having a maximum number of 10 electrons in it.
Therefore, one electron from 5s orbital jumps to 4d orbital to make it stable. Now, 5s orbital has only one electron, and it will be easy for silver to lose this electron to attain a stable electronic configuration.
