1. How many aluminum atoms are in a cube that is 10 nm on a side? (atomic mass of aluminum = 27 g/mole; Density of aluminum: 2.7 g/cm³; Avogadro's Number:6.02 x 10²³ atoms/mole)
2. On the stress-strain diagram below, indicate for each curve, the elastic range, the ductile range, and fracture. Which curve is for a brittle material? And which curve is for a metal?

\fE2 E2 - photon photon E1 E1