atnos They go from 57 to 71 in the lanthanide series: Abbr Proton counts: Abbr Periodic law figs Element info: abbr Chem. class data B's 5 and C's 6 92 for U and 53 for I: Abbr 92 and 53 for U and I 7 for N, 8 for O, etc. B and O figures: Abbr. Periodic law figs. Periodic table figs. 5 for B and 6 for C Chem. class figures 1 for H and 2 for He, e.g