17. Form similar pairs of words.
i. silver and ________ / oxygen and O
Hence, silver and Ag / oxygen and O.
ii. ________ and K / calcium and Ca
iii. PbO and lead oxide / ______ and lead sulfide
v. Sodium chloride and ________ / hydrogen chloride and HCl
iv. CO2 and Carbon dioxide / ______ and water
vi. N and atom of nitrogen / ______ and molecule of nitrogen