What is the Fermi energy of metallic potassium at 0K?

[joel.martens]

Homework Statement

We must calculate the Fermi energy of metallic potassium at 0K. We have aleady found the number of atoms per m cubed, we are told that each atom contributes one electron to the free electron gas.

Homework Equations

Fermi energy = ((hbar^2)/2m)(((3Pi^2)N)/V)^3/2

The Attempt at a Solution

My problem is that i don't know what V is supposed to be. I thought that since each K gives one electron to become K+, V might be +e, but that gave a nonsensical answer.

 

[joel.martens]

Need more info? better explanation?
Pls help!

 

[dx]

You don't need to know V, since the formula involves V only in the form N/V, i.e. the number of electrons per unit volume.

 

[joel.martens]

ooooooooooooooh, V for volume. Thankyou, i was stuck on thinking voltages.