[" 12.How many molecules are present in one gram of hydrogen "],[[" (a) "6.02times10^(23)," [AllMS 1982] "," by mass.The "],[" (c) "2.5times10^(23)," (b) "3.01times10^(23)," present in "10.0],[" (d) "1.5times10^(23)," (c) "10^(21)],[" 24.Which has the "]]