What is the observation of copper (s) plus silver nitrate?

Answer 1

Cu(s) + 2AgNO3(aq) --> 2Ag(s) + Cu(NO3)2(aq)

According to the metal activity series, copper is more reactive than silver, so the copper will replace the silver in the silver nitrate compound.
https://en.wikipedia.org/wiki/Reactivity_series

The silver metal will precipitate out of solution, forming along the piece of copper, which goes into solution, combining with the aqueous nitrate ion. If this reaction goes to completion, all of the copper will go into solution as copper(II) nitrate, and all of the silver metal will precipitate out of solution.

Answer 2

The chemical reaction is:
Cu + 2 AgNO3 = Cu(NO3)2 + Ag

Answer 3

A single replacement reaction will ensue which will produce elemental silver plus a bluish-colored copper(II) nitrate solution.