How do I write the reaction of copper metal with silver nitrate solution where the valency of copper is 2?

Metallic copper reacts with a solution of silver nitrate
to form a solution of copper(II) nitrate and the silver is precipitated. The equation
for this reaction can be written as Cu + AgNO3 ---> Cu(NO3)2 +
Ag.

This equation is not yet balanced as the number of
atoms of all the elements is not the same on both the
sides.

The equation can be balanced by first making the
number of AgNO3 atoms on the left equal to two to balance the NO3 ions. As this doubles
the number of Ag atoms, they have to be increased on the right hand side also. The
balanced equation of Cu reacting with AgNO3
is

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