{HEAD ~ The alkali metal cations} then accept electrons from electrode 18 and return to {TAIL ~ their elemental state} 
{ HEAD ~ The alkali metal cations } then accept electrons from electrode 18 and return to { TAIL ~ their elemental state }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL