The power source connected to {HEAD ~ the cells} produces {TAIL ~ a chemical reaction} that produces a flow of chlorine atoms into the body of water for purifying the body of water 
The power source connected to { HEAD ~ the cells } produces { TAIL ~ a chemical reaction } that produces a flow of chlorine atoms into the body of water for purifying the body of water
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH