Question

How can you determine the atomic mass of an unknown metal if you know its density and the dimension of its unit cell? Explain.

Answer 1

Let the length of the edge of the molecule be a and the density of the metal be d.

We know that m will be the atomic mass and the number of atoms which are present in on of the cell be z.

We know the density of the unit cell= mass of the unit cell/vol of the cell.

Again, the mass of the unit cell = Number of atoms in the unit cell X Atomic mass.

The volume of the unit cell = (Edge length of the cubic unit cell)

3 d=zm/a3 => m=da3/z; mass= atomic mass/Na=> M=da4Na/z; M=d(abc)Na/z( in case of cuboids).