[" 2.Volume occupied by one molecule of water "],[[" (density a gem ) is : "," ud "],[" (1) "3.0times10^(-21)cm," (2) "5.5times10^(-23)cm^(3)],[" (3"9.0times10^(-3)cm^(3)," (4) "6.023times10^(-23)cm^(3)]]