chemistry
posted by kylie .
one edge of a cube is measured and found to be 2.162 cm. An atom of copper is 0.2560 nm in diameter. how many atoms of copper are contained in the cube.

I would do this. I don't think it is an exact way but...
0.2560 nm = 2.56E8 cm diameter so how many can be placed on an edge length. That will be 2.56E8 cm x # atoms = 2.162 cm and solve for # atoms. Then cube that. I think that will over count because the end atom (and there are two ends) will be counted twice and the corner atoms will be counted three times.