Answer:
id say D
Explanation:
because its the only answer that has to do with colors and visable light
but A and B also have to do with eachother so i feel like it could be with one of those but it def isnt C
I am sorry if i am wrong, let me know tho!
Answer:
The number of free electrons per cubic meter is 
Explanation:
It is given that,
The number of free electrons per cubic meter is, 1.3
Electrical conductivity of metal, 
Density of metal, 
Atomic weight, A = 107.87 g/mol
Let n is the number of free electrons per cubic meter such that,


Where
is the density of silver atom
is the Avogadro number
A is the atomic weight of silver


or

Hence, this is the required solution.