They were contained in the liquid membrane ready to attach themselves to a copper ion but only when it had been reduced to Cu +.
In a little while, the liquid may take on some coloring from the copper ions it has dissolved.
The copper ions are very strongly contained within the stable silicate structure.
Thus, zinc metal will lose electrons to copper ions and develop a positive electrical charge.
However, some fungi are capable of adapting to elevated levels of copper ions.
In the presence of chlorine, copper ions emit a deep blue light.
Only the proportion of copper ions is relatively high for human consumption but this use is still safe.
I'm reading minute traces of copper ions in the lead chamber.
Its purpose was to provide a chlorine donor to enhance the green and blue colours from copper ions in the flame.
The iron oxidizes, and the copper ions are reduced through the transfer of electrons.