.ANSWER:Copper is a ductile metal
EXPLAIN :This means that it can easily be shaped into pipes and drawn into wires. Copper pipes are lightweight because they can have thin walls. They don't corrode and they can be bent to fit around corners.
Cobalt sulphate is the usual source of water-soluble cobalt since it is the most economical salt and shows less tendency to deliquesce or dehydrate
Nitrous Acid.
Hyponitrous acid: H2N2O2
Nitric acid: HNO3
Pernitric acid: HNO