cies ▁among ▁nomin ally ▁lower ▁ ▁states   – ▁a ▁phenomen on ▁un seen ▁in ▁l ighter ▁elements . ▁Con tr ary , ▁seven ▁elements ▁from ▁z inc ▁to ▁k rypt on ▁are ▁the ▁heav iest ▁where ▁all ▁electron ▁shell s ▁below ▁the ▁val ence ▁shell ▁are ▁filled ▁completely . ▁This ▁isn ' t ▁possible ▁in ▁further ▁periods ▁due ▁to ▁existence ▁of ▁f - sub sh ells ▁starting ▁from ▁. ▁ ▁List ▁of ▁elements ▁{ | ▁class =" wik itable ▁sort able " ▁! ▁col span =" 3 " ▁| ▁Chem ical ▁element ▁! ▁Chem ical ▁series ▁! ▁Electron ▁configuration ▁| - ▁! ▁  ▁! ▁! ▁! ▁! ▁| - ▁style =" background :# f 6 6 ;" ▁|| ▁ 1 9 ▁ ▁|| ▁K ▁|| ▁Pot ass ium ▁|| ▁Al k ali ▁metal ▁|| ▁[ Ar ] ▁ 4 s 1 ▁| - ▁style =" background :# ff de ad ;" ▁|| ▁ 2 0 ▁ ▁|| ▁Ca ▁|| ▁Cal ci um ▁|| ▁Al kal ine ▁earth ▁metal ▁|| ▁[ Ar ] ▁ 4 s 2 ▁| - ▁style =" background :# ff c 0 c 0 ;" ▁|| ▁ 2 1 ▁ ▁|| ▁Sc ▁|| ▁Sc and ium ▁|| ▁Trans ition ▁metal ▁|| ▁[ Ar ] ▁ 3 d 1 ▁ 4 s 2 ▁| - ▁style =" background :# ff c 0 c 0 ;" ▁|| ▁ 2 2 ▁ ▁|| ▁Ti ▁|| ▁T itan ium ▁|| ▁Trans ition ▁metal ▁|| ▁[ Ar ] ▁ 3 d 2 ▁ 4