2=269×1025m3 或n=NV0=602×1023/224×103 =269×1025m-3 (2)=1.60X√Rr =160√8.31×273/29×10 3=448m.s (3)z=√2nd n y =141×3,14×(35×10-02x2.6XO25×448 =6.54×103sn N0 V0 或 = / 6.02 10 /22.4 10 23 −3 =   2.69 10 m 25 −3 =  448m s 1 =  − 1.60 8.31 273/29 10−3 =   (2)v =1.60 RT / m 6.54 10 s 9 −1 =  Z d n v 2 (3) = 2 1.41 3.14 (3.5 10 ) 2.69 10 448 10 2 25 =       − 2.69 10 m 25 −3 n = 