When H2S gas is passed in a metal sulphate solution in presence of NH4OH, a white precipitate is produced. The metal is identified as:
Zn
Fe
Pb
Hg
Which of the following is philosopher's wool ?
ZnO
HgO
Ag2O
CuO
A.
ZnO
ZnO is known as philosopher's wool because it is very light, white, soft wooly powder.
84Rn219 is a member of actinium series. The other member of this series is-
89Ac225
90Th232
15P35
92U235