【正确答案】(1) 4r =a a = (4r) /= (4 ′ 175) /= 495 (pm) (2) 金属Pb单元晶胞中有4个Pb原子，占有体积VPb = 4 ′ 晶胞体积 V晶胞= a3 = ()3 Pb的空间占有率 =′100 /% ==′100 /% = 0.74 ′ 100 /% = 74 /% M·n `&12` (3) Pb的密度= 11.3 (g·cm-3)