in the negative eog-generating process a cation which can substitute for na ( + ) was sought among the monovalent ions , li ( + ) , rb ( + ) , cs ( + ) , nh ( 4 ) ( + ) , and tea ( + ) , the divalent ions , mg ( ++ ) , ca ( ++ ) , sr ( ++ ) , ba ( ++ ) , zn ( ++ ) , cd ( ++ ) , mn ( ++ ) , co ( ++ ) , and ni ( ++ ) , and the trivalent ions , al ( +++ ) and fe ( +++ ) .
C0007447
cation
C0022023
ions