- #1

- 123

- 0

## Homework Statement

a) A material is composed of two atoms, A with effecitve radius 2.00 angstroms and B with effective radius 3.10 angstroms. The lattice is a body-centred lattice.

b)Enter the volume density of either the A or B atoms in atoms/cm3

## Homework Equations

.5*sqrt3=(r1+r2)

surface density=# of atoms per lattice plane/area of lattice plane

## The Attempt at a Solution

a)

a=((3.10A+2.0A)*2)/(sqrt3)

a=5.89 A (Lattice constant) (correct)

b) In part B I keep getting the wrong answer.

The equation I'm using is surface density=# of atoms/area of lattice plane

So...

# of atoms should be 2 for a body centered cube

2/(5.89*10^-8)^3 = 9.79*10^21 atoms/cm^2 (incorrect)

Last edited: