Relatively {TAIL ~ base metals} such as {HEAD ~ lead} and cadmium, specifically, may pass into solution in aqueous and especially in increasingly acid environment, decomposing water and liberating hydrogen 
Relatively { TAIL ~ base metals } such as { HEAD ~ lead } and cadmium , specifically , may pass into solution in aqueous and especially in increasingly acid environment , decomposing water and liberating hydrogen
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH