A.453,477,493nm B.453,465,477nm C.450,460,470nm D.444,468,490nm
A.No.1.670Ne1.654 B.相對密度2.95 C.硬度7.5 D.三方晶系
A.二碘甲烷 B.二碘乙烯 C.四碘乙烯 D.三溴甲烷