The accompanying figure shows three different crystallographic planes for a unit cell of some hypothetical metal. The circles represent atoms:

(a) To what crystal system does the unit cell belong?
(b) What would this crystal structure be called?
(c) If the density of this metal is 18.91 g/cm3, determine its atomic weight?

| 0.25 nm 0.20 nm (110) (101) (011) 0.39 nm K-0.32 nm> K-0.36 nm