Answer:

Step-by-step explanation:
We know that unit cell of silver is FCC.
In FCC

Plane [111] is passing through the center of cell diagonally.In this plane half part of atoms comes under that plane.
So Z= 2 x 1/2 =1
Z = 1 atom (in plane (1,1,1))
The length of vector
given as
![d_{[111]=2R\sqrt6](https://img.qammunity.org/2020/formulas/engineering/college/txirz1dhu1l4860ufag4hu1l4qolscybbo.png)
We know that linear density(LD) given as
![LD=(Number\ of\ atoms\ in\ the\ direction\ vector)/(d_([111]))](https://img.qammunity.org/2020/formulas/engineering/college/opjte96ywnaci4fo33t4e0fuek21658z8j.png)

We know that for silver
R=0.144 nm

