# Cristaline structure: simple solid state physics problem

1. Mar 9, 2014

### Jalo

1. The problem statement, all variables and given/known data

The atomic mass of Niquel is 58.7 amu (atomic mass unit), and it's density (at 90ºC) is 8.86 g/cm³.

(a) Find the distance from one atom to the closest one from him.

2. Relevant equations

1 amu = 1.66053*19⁻²⁷

3. The attempt at a solution

I started by finding the number of atoms per cm³, N:

$N = \frac{8.86*10^{24}}{1.66053} = 5.3356*10^{24} atoms/cm^{3}$

This is where I lose myself. Am I supposed to solve this without knowing the type of unit cell? If I knew it, since I know the number of atoms per cell, I would be able to get the length of the side of the unit cell, and from there I could work out the distance between two atoms next to each other.

Is there a way to solve this without knowing the unit cell before hand? Or am I supposed to solve it by searching the correct unit cell and following the line of thought I wrote?
D.

2. Mar 10, 2014

### ehild

You can browse for "Crystal structure of Nickel" or see the Periodic Table http://en.wikipedia.org/wiki/Periodic_table_(crystal_structure)

When calculating the number of atoms in 1 cm3, you have to consider the atomic mass of Nickel. Your result is wrong.

ehild