N/P ratio

Si has 6 N and 6 P in the first C nuclet, Si has 3 N in the neutral 5 ending, Si has 6 P in the C ending nuclet making a total of 14 P and 14 N = 28 (Z)

It is clear that the second carbon nuclet has not the 6/6 P/N ratio of the single Carbon but since all other C nuclet contain only 11 new P, the ratio changes to 5 N and 6 P per C nuclet (all but the first).