An electron moving with initial velocity v0 = 8.6x105 m / s penetrates a region where the electric field equals e = 4.1x10^3 n / c. calculate: a) the time it takes for the electron to reach rest; b) the distance traveled by it before stopping.

Ahypothetical metal has an orthorhombic unit cell for which the a, b, and c lattice parameters are 0.413 nm, 0.665 nm, and 0.876 nm, respectively. (a) if there are 8 atoms per unit cell and the atomic packing factor is 0.536, determine the atomic radius (in nm). (b) if the density is 3.99 g/cm3, calculate the metal's atomic weight (in g/mol).