To provide some perspective on the dimensions of atomic defects in solids, consider a metal specimen that has a dislocation density of 10^4 mm^-2. Suppose that all the dislocations in 1 cm^3 were somehow removed and linked end-to-end. How far (in km) would the chain extend? Now suppose that the density is increased to 10^10mm^-2 by cold working. What would the chain length of dislocations in 1 cm^3 of material? Can anyone help me with this question, it has me stumped.