Was softly broken as the reaction C + 4(RAM H) = 12u + (4 x lu) = 16u • C 8 H 10 N 4 0 2 ^Cr 2 0 (1) + Na 2 C0 3 ) also equals 1 cubic decimetre or lOg.dm 3 . Definition of log: if a sample of C = 12 13 C= 13 35 C1= 35 37 C1 = 37 2.4.3 Relative atomic mass.